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Sample records for brain hsp90 studied

  1. Phosphorylation and oligomerization states of native pig brain HSP90 studied by mass spectrometry

    DEFF Research Database (Denmark)

    Garnier, C.; Lafitte, D.; Jorgensen, T.J.;

    2001-01-01

    HSP90 purified from pig brain. The two protein isoforms were clearly distinguished by ESI-MS, the alpha isoform being approximately six times more abundant than the beta isoform. ESI-MS in combination with lambda phosphatase treatment provided direct evidence of the existence of four phosphorylated...... such as actin-microfilament, tubulin-microtubule and intermediate filaments, and also exhibits conventional chaperone functions. This protein exists in two isoforms alpha-HSP90 and beta-HSP90, and it forms dimers which are crucial species for its biological activity. PAGE, ESI-MS and MALDI-MS were used to study...... forms of native pig brain alpha-HSP90, with the diphosphorylated form being the most abundant. For the beta isoform, the di-phosphorylated was also the most abundant. MALDI mass spectra of HSP90 samples after chemical cross-linking showed a high percentage of alpha-alpha homodimers. In addition...

  2. Decreased Hsp90 expression in infiltrative lobular carcinoma: an immunohistochemical study

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    Zagouri Flora

    2010-08-01

    Full Text Available Abstract Background Elevated Hsp90 expression has been documented in breast ductal carcinomas, whereas decreased Hsp90 expression has been reported in precursor lobular lesions. This study aims to assess Hsp90 expression in infiltrative lobular carcinomas of the breast. Methods Tissue specimens were taken from 32 patients with infiltrative lobular carcinoma. Immunohistochemical assessment of Hsp90 was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. Concerning Hsp90 assessment: i the percentage of positive cells and ii the intensity were separately analyzed. Subsequently, the Allred score was adopted and calculated. The intensity was treated as an ordinal variable-score (0: negative, low: 1, moderate: 2, high: 3. Statistical analysis followed. Results All infiltrative lobular carcinoma foci mainly presented with a positive cytoplasmic immunoreaction for Hsp90. Compared to the adjacent normal ducts and lobules, infiltrative lobular carcinoma exhibited a statistically significant decrease in Hsp90 expression, both in terms of Hsp90 positive cells (% and Allred score (74.2 ± 11.2 vs. 59.1 ± 14.2 p = 0.0001; 7.00 ± 0.95 vs. 6.22 ± 1.01, p = 0.007, Wilcoxon matched-pairs signed-ranks test. Concerning the intensity of Hsp90 immunostaining only a marginal decrease was noted (2.16 ± 0.68 vs. 1.84 ± 0.63, p = 0.087, Wilcoxon matched-pairs signed-ranks test. Conclusion ILC lesions seem to exhibit decreased Hsp90 expression, a finding contrary to what might have been expected, given that high Hsp90 expression is a trait of invasive ductal carcinomas.

  3. Molecular docking study, synthesis and biological evaluation of Schiff bases as Hsp90 inhibitors.

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    Dutta Gupta, Sayan; Snigdha, D; Mazaira, Gisela I; Galigniana, Mario D; Subrahmanyam, C V S; Gowrishankar, N L; Raghavendra, N M

    2014-04-01

    Heat shock protein 90 (Hsp90) is an emerging attractive target for the discovery of novel cancer therapeutic agents. Docking methods are powerful in silico tools for lead generation and optimization. In our mission to rationally develop novel effective small molecules against Hsp90, we predicted the potency of our designed compounds by Sybyl surflex Geom X docking method. The results of the above studies revealed that Schiff bases derived from 2,4-dihydroxy benzaldehyde/5-chloro-2,4-dihydroxy benzaldehyde demonstrated effective binding with the protein. Subsequently, a few of them were synthesized (1-10) and characterized by IR, (1)HNMR and mass spectral analysis. The synthesized molecules were evaluated for their potential to suppress Hsp90 ATPase activity by Malachite green assay. The anticancer studies were performed by 3-(4,5-dimethythiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method. The software generated results was in satisfactory agreement with the evaluated biological activity.

  4. Spontaneous assembly of HSP90 inhibitors at water/octanol interface: A molecular dynamics simulation study

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    Zolghadr, Amin Reza; Boroomand, Samaneh

    2017-02-01

    Drug absorption at an acceptable dose depends on the pair of solubility and permeability. There are many potent therapeutics that are not active in vivo, presumably due to the lack of capability to cross the cell membrane. Molecular dynamics simulation of radicicol, diol-radicicol, cyclopropane-radicicol and 17-DMAG were performed at water/octanol interface to suggest interfacial activity as a physico-chemical characteristic of these heat shock protein 90 (HSP90) inhibitors. We have observed that orally active HSP90 inhibitors form aggregates at the water/octanol and DPPC-lipid/water interfaces by starting from an initial configuration with HSP90 inhibitors embedded in the water matrix.

  5. Search for Hsp90 inhibitors with potential anticancer activity: isolation and SAR studies of radicicol and monocillin I from two plant-associated fungi of the Sonoran desert.

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    Turbyville, Thomas J; Wijeratne, E M Kithsiri; Liu, Manping X; Burns, Anna M; Seliga, Christopher J; Luevano, Libia A; David, Cynthia L; Faeth, Stanley H; Whitesell, Luke; Gunatilaka, A A Leslie

    2006-02-01

    In an effort to discover small molecule inhibitors of Hsp90, we have screened over 500 EtOAc extracts of Sonoran desert plant-associated fungi using a two-stage strategy consisting of a primary cell-based heat shock induction assay (HSIA) followed by a secondary biochemical luciferase refolding assay (LRA). Bioassay-guided fractionation of extracts active in these assays derived from Chaetomium chiversii and Paraphaeosphaeria quadriseptata furnished the Hsp90 inhibitors radicicol (1) and monocillin I (2), respectively. In SAR studies, 1, 2, and their analogues, 3-16, were evaluated in these assays, and the antiproliferative activity of compounds active in both assays was determined using the breast cancer cell line MCF-7. Radicicol and monocillin I were also evaluated in a solid-phase competition assay for their ability to bind Hsp90 and to deplete cellular levels of two known Hsp90 client proteins with relevance to breast cancer, estrogen receptor (ER), and the type 1 insulin-like growth factor receptor (IGF-1R). Some inferences on SAR were made considering the crystal structure of the N-terminus of yeast Hsp90 bound to 1 and the observed biological activities of 1-16. Isolation of radicicol and monocillin I in this study provides evidence that we have developed an effective strategy for discovering natural product-based Hsp90 inhibitors with potential anticancer activity.

  6. Studies on effect of different seasons on expression of HSP70 and HSP90 gene in sperm of Tharparkar bull semen

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    J.S. Rajoriya

    2014-09-01

    Conclusion: It was concluded from the present study that there was no significant difference in the mRNA expression of HSP 70 and HSP 90 between the winter and summer season, presence of similar type of stress resistant spermatozoa in Tharparkar bull semen and the semen can be cryopreserved throughout the year in this prestigious Indian breed.

  7. Hsp90 inhibition decreases mitochondrial protein turnover.

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    Daciana H Margineantu

    Full Text Available BACKGROUND: Cells treated with hsp90 inhibitors exhibit pleiotropic changes, including an expansion of the mitochondrial compartment, accompanied by mitochondrial fragmentation and condensed mitochondrial morphology, with ultimate compromise of mitochondrial integrity and apoptosis. FINDINGS: We identified several mitochondrial oxidative phosphorylation complex subunits, including several encoded by mtDNA, that are upregulated by hsp90 inhibitors, without corresponding changes in mRNA abundance. Post-transcriptional accumulation of mitochondrial proteins observed with hsp90 inhibitors is also seen in cells treated with proteasome inhibitors. Detailed studies of the OSCP subunit of mitochondrial F1F0-ATPase revealed the presence of mono- and polyubiquitinated OSCP in mitochondrial fractions. We demonstrate that processed OSCP undergoes retrotranslocation to a trypsin-sensitive form associated with the outer mitochondrial membrane. Inhibition of proteasome or hsp90 function results in accumulation of both correctly targeted and retrotranslocated mitochondrial OSCP. CONCLUSIONS: Cytosolic turnover of mitochondrial proteins demonstrates a novel connection between mitochondrial and cytosolic compartments through the ubiquitin-proteasome system. Analogous to defective protein folding in the endoplasmic reticulum, a mitochondrial unfolded protein response may play a role in the apoptotic effects of hsp90 and proteasome inhibitors.

  8. Hsp90 C-terminal inhibitors exhibit antimigratory activity by disrupting the Hsp90α/Aha1 complex in PC3-MM2 cells.

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    Ghosh, Suman; Shinogle, Heather E; Garg, Gaurav; Vielhauer, George A; Holzbeierlein, Jeffrey M; Dobrowsky, Rick T; Blagg, Brian S J

    2015-02-20

    Human Hsp90 isoforms are molecular chaperones that are often up-regulated in malignances and represent a primary target for Hsp90 inhibitors undergoing clinical evaluation. Hsp90α is a stress-inducible isoform of Hsp90 that plays a significant role in apoptosis and metastasis. Though Hsp90α is secreted into the extracellular space under metastatic conditions, its role in cancer biology is poorly understood. We report that Hsp90α associates with the Aha1 co-chaperone and found this complex to localize in secretory vesicles and at the leading edge of migrating cells. Knockdown of Hsp90α resulted in a defect in cell migration. The functional role of Hsp90α/Aha1 was studied by treating the cells with various novobiocin-based Hsp90 C-terminal inhibitors. These inhibitors disrupted the Hsp90α/Aha1 complex, caused a cytoplasmic redistribution of Hsp90α and Aha1, and decreased cell migration. Structure-function studies determined that disruption of Hsp90α/Aha1 association and inhibition of cell migration correlated with the presence of a benzamide side chain, since an acetamide substituted analog was less effective. Our results show that disruption of Hsp90α/Aha1 interactions with novobiocin-based Hsp90 C-terminal inhibitors may limit the metastatic potential of tumors.

  9. Calcium/calmodulin kinase1 and its relation to thermotolerance and HSP90 in Sporothrix schenckii: an RNAi and yeast two-hybrid study

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    Gonzalez-Mendez Ricardo

    2011-07-01

    Full Text Available Abstract Background Sporothrix schenckii is a pathogenic dimorphic fungus of worldwide distribution. It grows in the saprophytic form with hyaline, regularly septated hyphae and pyriform conidia at 25°C and as the yeast or parasitic form at 35°C. Previously, we characterized a calcium/calmodulin kinase in this fungus. Inhibitors of this kinase were observed to inhibit the yeast cell cycle in S. schenckii. Results The presence of RNA interference (RNAi mechanism in this fungus was confirmed by the identification of a Dicer-1 homologue in S. schenckii DNA. RNAi technology was used to corroborate the role of calcium/calmodulin kinase I in S. schenckii dimorphism. Yeast cells were transformed with the pSilent-Dual2G (pSD2G plasmid w/wo inserts of the coding region of the calcium/calmodulin kinase I (sscmk1 gene. Transformants were selected at 35°C using resistance to geneticin. Following transfer to liquid medium at 35°C, RNAi transformants developed as abnormal mycelium clumps and not as yeast cells as would be expected. The level of sscmk1 gene expression in RNAi transformants at 35°C was less than that of cells transformed with the empty pSD2G at this same temperature. Yeast two-hybrid analysis of proteins that interact with SSCMK1 identified a homologue of heat shock protein 90 (HSP90 as interacting with this kinase. Growth of the fungus similar to that of the RNAi transformants was observed in medium with geldanamycin (GdA, 10 μM, an inhibitor of HSP90. Conclusions Using the RNAi technology we silenced the expression of sscmk1 gene in this fungus. RNAi transformants were unable to grow as yeast cells at 35°C showing decreased tolerance to this temperature. The interaction of SSCMK1 with HSP90, observed using the yeast two-hybrid assay suggests that this kinase is involved in thermotolerance through its interaction with HSP90. SSCMK1 interacted with the C terminal domain of HSP90 where effector proteins and co-chaperones interact. These

  10. Tumor-intrinsic and tumor-extrinsic factors impacting hsp90- targeted therapy.

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    Alarcon, S V; Mollapour, M; Lee, M-J; Tsutsumi, S; Lee, S; Kim, Y S; Prince, T; Apolo, A B; Giaccone, G; Xu, W; Neckers, L M; Trepel, J B

    2012-11-01

    In 1994 the first heat shock protein 90 (Hsp90) inhibitor was identified and Hsp90 was reported to be a target for anticancer therapeutics. In the past 18 years there have been 17 distinct Hsp90 inhibitors entered into clinical trial, and the small molecule Hsp90 inhibitors have been highly valuable as probes of the role of Hsp90 and its client proteins in cancer. Although no Hsp90 inhibitor has achieved regulatory approval, recently there has been significant progress in Hsp90 inhibitor clinical development, and in the past year RECIST responses have been documented in HER2-positive breast cancer and EML4-ALK-positive non-small cell lung cancer. All of the clinical Hsp90 inhibitors studied to date are specific in their target, i.e. they bind exclusively to Hsp90 and two related heat shock proteins. However, Hsp90 inhibitors are markedly pleiotropic, causing degradation of over 200 client proteins and impacting critical multiprotein complexes. Furthermore, it has only recently been appreciated that Hsp90 inhibitors can, paradoxically, cause transient activation of the protein kinase clients they are chaperoning, resulting in initiation of signal transduction and significant physiological events in both tumor and tumor microenvironment. An additional area of recent progress in Hsp90 research is in studies of the posttranslational modifications of Hsp90 itself and Hsp90 co-chaperone proteins. Together, a picture is emerging in which the impact of Hsp90 inhibitors is shaped by the tumor intracellular and extracellular milieu, and in which Hsp90 inhibitors impact tumor and host on a microenvironmental and systems level. Here we review the tumor intrinsic and extrinsic factors that impact the efficacy of small molecules engaging the Hsp90 chaperone machine.

  11. Hsp90 selectively modulates phenotype in vertebrate development.

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    Patricia L Yeyati

    2007-03-01

    Full Text Available Compromised heat shock protein 90 (Hsp90 function reveals cryptic phenotypes in flies and plants. These observations were interpreted to suggest that this molecular stress-response chaperone has a capacity to buffer underlying genetic variation. Conversely, the protective role of Hsp90 could account for the variable penetrance or severity of some heritable developmental malformations in vertebrates. Using zebrafish as a model, we defined Hsp90 inhibitor levels that did not induce a heat shock response or perturb phenotype in wild-type strains. Under these conditions the severity of the recessive eye phenotype in sunrise, caused by a pax6b mutation, was increased, while in dreumes, caused by a sufu mutation, it was decreased. In another strain, a previously unobserved spectrum of severe structural eye malformations, reminiscent of anophthalmia, microphthalmia, and nanophthalmia complex in humans, was uncovered by this limited inhibition of Hsp90 function. Inbreeding of offspring from selected unaffected carrier parents led to significantly elevated malformation frequencies and revealed the oligogenic nature of this phenotype. Unlike in Drosophila, Hsp90 inhibition can decrease developmental stability in zebrafish, as indicated by increased asymmetric presentation of anophthalmia, microphthalmia, and nanophthalmia and sunrise phenotypes. Analysis of the sunrise pax6b mutation suggests a molecular mechanism for the buffering of mutations by Hsp90. The zebrafish studies imply that mild perturbation of Hsp90 function at critical developmental stages may underpin the variable penetrance and expressivity of many developmental anomalies where the interaction between genotype and environment plays a major role.

  12. Phage displaying epitope of Candida albicans HSP90 and serodiagnosis

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    杨琼; 王丽; 卢大宁; 邢沈阳; 尹东; 朱筱娟

    2004-01-01

    @@ Recently, the frequent use of immunosuppressants and chemotherapeutic drugs for cancers has caused an increase in the frequency of life-threatening systemic candidiasis.1 Studies by Matthews et al2 indicated HSP90 fragments are major targets for the immune system in infection due to C. albicans, and anti-epitope LKVIRK of HSP90 antibody is a serological marker for diagnosis of invasive candidiasis. Cloning and sequencing HSP90 antigen revealed that the linear epitope LKVIRK, localized near the C-terminus of the 47 kDa protein which circulates in the sera of patients with invasive candidiasis, as a heat-stable breakdown product of large more heat-labile antigen HSP90.2 In this study, epitope LKVIRK was displayed on the surface of phage fd to develop a new serological test for systemic candidiasis.

  13. Perbedaan Kadar HSP90 pada Preeklamsi Berat dengan Kehamilan Normal

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    Soetrisno

    2015-06-01

    Full Text Available Severe pre-eclampsia is the second highest cause of maternal mortality. Free radicals that stimulate heat shock protein 90 (HSP 90 are believed to determine severe pre-eclampsia. HSP90 is an important protein that helps the establishment and maintenance of other proteins. It also increases the life time of cells after various pathological conditions (chaperone function. The chaperone function is the adaptation key factor to endogenous stress in tissues. By recognizing HSP90 level in early detection of severe pre-eclampsia, prevention and management can be started early. This study aimed to prove that the HSP90 level in pregnancy with severe pre-eclampsia is higher than normal pregnancy. This was a quantitative study using cross sectional approach by testing the HSP90 level. The study was conducted during the period of September to November 2013, at the Obstetrics and Gynecological Unit, Moewardi Hospital Surakarta and Prodia Laboratory Jakarta. The number of subjects was 30 patients, consisting of 15 normal pregnant mothers and 15 pregnant mothers with pre-eclampsia . The calculation of serum HSP90 level was conducted using enzyme-linked immunosorbent assay (ELISA. Data were analyzed using t-test using SPSS for Windows version 17 for Windows. The mean of HSP90 in the severe pre-eclampsia group was 131.91±26.66 while the mean in the normal pregnancy group was 80.28±13.39 with p=0.00 (p<0.05. Level of HSP90 serum in severe pre-eclampsia is higher than in normal pregnancy, due to the occurrence of oxidative stress in severe pre-eclampsia

  14. Hsp90 inhibition accelerates cell lysis. Anti-Hsp90 ribozyme reveals a complex mechanism of Hsp90 inhibitors involving both superoxide- and Hsp90-dependent events.

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    Sreedhar, Amere Subbarao; Mihály, Katalin; Pató, Bálint; Schnaider, Tamás; Steták, Attila; Kis-Petik, Katalin; Fidy, Judit; Simonics, Tibor; Maraz, Anna; Csermely, Péter

    2003-09-12

    The 90 kDa heat shock protein, Hsp90, is an abundant molecular chaperone participating in the cytoprotection of eukaryotic cells. Here we analyzed the involvement of Hsp90 in the maintenance of cellular integrity using partial cell lysis as a measure. Inhibition of Hsp90 by geldanamycin, radicicol, cisplatin, and novobiocin induced a significant acceleration of detergent- and hypotonic shock-induced cell lysis. The concentration and time dependence of cell lysis acceleration was in agreement with the Hsp90 inhibition characteristics of the N-terminal inhibitors, geldanamycin and radicicol. Glutathione and other reducing agents partially blocked geldanamycin-induced acceleration of cell lysis but were largely ineffective with other inhibitors. Indeed, geldanamycin treatment led to superoxide production and a change in membrane fluidity. When Hsp90 content was diminished using anti-Hsp90 hammerhead ribozymes, an accelerated cell lysis was also observed. Hsp90 inhibition-induced cell lysis was more pronounced in eukaryotic (yeast, mouse red blood, and human T-lymphoma) cells than in bacteria. Our results indicate that besides the geldanamycin-induced superoxide production, and a consequent increase in cell lysis, inhibition or lack of Hsp90 alone can also compromise cellular integrity. Moreover, cell lysis after hypoxia and complement attack was also enhanced by any type of Hsp90 inhibition used, which shows that the maintenance of cellular integrity by Hsp90 is important in physiologically relevant lytic conditions of tumor cells.

  15. Comparative genomics and evolution of the HSP90 family of genes across all kingdoms of organisms

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    Zhong Daibin

    2006-06-01

    Full Text Available Abstract Background HSP90 proteins are essential molecular chaperones involved in signal transduction, cell cycle control, stress management, and folding, degradation, and transport of proteins. HSP90 proteins have been found in a variety of organisms suggesting that they are ancient and conserved. In this study we investigate the nuclear genomes of 32 species across all kingdoms of organisms, and all sequences available in GenBank, and address the diversity, evolution, gene structure, conservation and nomenclature of the HSP90 family of genes across all organisms. Results Twelve new genes and a new type HSP90C2 were identified. The chromosomal location, exon splicing, and prediction of whether they are functional copies were documented, as well as the amino acid length and molecular mass of their polypeptides. The conserved regions across all protein sequences, and signature sequences in each subfamily were determined, and a standardized nomenclature system for this gene family is presented. The proeukaryote HSP90 homologue, HTPG, exists in most Bacteria species but not in Archaea, and it evolved into three lineages (Groups A, B and C via two gene duplication events. None of the organellar-localized HSP90s were derived from endosymbionts of early eukaryotes. Mitochondrial TRAP and endoplasmic reticulum HSP90B separately originated from the ancestors of HTPG Group A in Firmicutes-like organisms very early in the formation of the eukaryotic cell. TRAP is monophyletic and present in all Animalia and some Protista species, while HSP90B is paraphyletic and present in all eukaryotes with the exception of some Fungi species, which appear to have lost it. Both HSP90C (chloroplast HSP90C1 and location-undetermined SP90C2 and cytosolic HSP90A are monophyletic, and originated from HSP90B by independent gene duplications. HSP90C exists only in Plantae, and was duplicated into HSP90C1 and HSP90C2 isoforms in higher plants. HSP90A occurs across all

  16. Tissue-specific induction of Hsp90 mRNA and plasma cortisol response in chinook salmon following heat shock, seawater challenge, and handling challenge

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    Palmisano, Aldo N.; Winton, J.R.; Dickhoff, Walton W.

    2000-01-01

    In studying the whole-body response of chinook salmon (Oncorhynchus tshawytscha) to various stressors, we found that 5-hour exposure to elevated temperature (mean 21.6??C; + 10.6??C over ambient) induced a marked increase in Hsp90 messenger RNA accumulation in heart, brain, gill, muscle, liver, kidney, and tail fin tissues. The most vital tissues (heart, brain, gill, and muscle) showed the greatest Hsp90-mRNA response, with heart tissue increasing approximately 35-fold, Heat shock induced no increase in plasma cortisol. In contrast, a standard handling challenge induced high plasma cortisol levels, but no elevation in Hsp90 mRNA in any tissue, clearly separating the physiological and cellular stress responses. We saw no increase either in tissue Hsp90 mRNA levels or in plasma cortisol concentrations after exposing the fish to seawater overnight.

  17. Constitutively-active androgen receptor variants function independently of the HSP90 chaperone but do not confer resistance to HSP90 inhibitors.

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    Gillis, Joanna L; Selth, Luke A; Centenera, Margaret M; Townley, Scott L; Sun, Shihua; Plymate, Stephen R; Tilley, Wayne D; Butler, Lisa M

    2013-05-01

    The development of lethal, castration resistant prostate cancer is associated with adaptive changes to the androgen receptor (AR), including the emergence of mutant receptors and truncated, constitutively active AR variants. AR relies on the molecular chaperone HSP90 for its function in both normal and malignant prostate cells, but the requirement for HSP90 in environments with aberrant AR expression is largely unknown. Here, we investigated the efficacy of three HSP90 inhibitors, 17-AAG, HSP990 and AUY922, against clinically-relevant AR missense mutants and truncated variants. HSP90 inhibition effectively suppressed the signaling of wild-type AR and all AR missense mutants tested. By contrast, two truncated AR variants, AR-V7 and ARv567es, exhibited marked resistance to HSP90 inhibitors. Supporting this observation, nuclear localization of the truncated AR variants was not affected by HSP90 inhibition and AR variant:HSP90 complexes could not be detected in prostate cancer cells. Interestingly, HSP90 inhibition resulted in accumulation of AR-V7 and ARv567es in both cell lines and human tumor explants. Despite the apparent independence of AR variants from HSP90 and their treatment-associated induction, the growth of cell lines with endogenous or enforced expression of AR-V7 or ARv567es remained highly sensitive to AUY922. This study demonstrates that functional AR variant signaling does not confer resistance to HSP90 inhibition, yields insight into the interaction between AR and HSP90 and provides further impetus for the clinical application of HSP90 inhibitors in advanced prostate cancer.

  18. The Double-Edged Sword: Conserved Functions of Extracellular Hsp90 in Wound Healing and Cancer

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    Hance, Michael W.; Nolan, Krystal D.; Isaacs, Jennifer S., E-mail: isaacsj@musc.edu [Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Hollings Cancer Center, Charleston, SC 29412 (United States)

    2014-05-06

    Heat shock proteins (Hsps) represent a diverse group of chaperones that play a vital role in the protection of cells against numerous environmental stresses. Although our understanding of chaperone biology has deepened over the last decade, the “atypical” extracellular functions of Hsps have remained somewhat enigmatic and comparatively understudied. The heat shock protein 90 (Hsp90) chaperone is a prototypic model for an Hsp family member exhibiting a duality of intracellular and extracellular functions. Intracellular Hsp90 is best known as a master regulator of protein folding. Cancers are particularly adept at exploiting this function of Hsp90, providing the impetus for the robust clinical development of small molecule Hsp90 inhibitors. However, in addition to its maintenance of protein homeostasis, Hsp90 has also been identified as an extracellular protein. Although early reports ascribed immunoregulatory functions to extracellular Hsp90 (eHsp90), recent studies have illuminated expanded functions for eHsp90 in wound healing and cancer. While the intended physiological role of eHsp90 remains enigmatic, its evolutionarily conserved functions in wound healing are easily co-opted during malignancy, a pathology sharing many properties of wounded tissue. This review will highlight the emerging functions of eHsp90 and shed light on its seemingly dichotomous roles as a benevolent facilitator of wound healing and as a sinister effector of tumor progression.

  19. Hsp90 governs echinocandin resistance in the pathogenic yeast Candida albicans via calcineurin.

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    Sheena D Singh

    2009-07-01

    Full Text Available Candida albicans is the leading fungal pathogen of humans, causing life-threatening disease in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs whose efficacy is compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. We previously established that the molecular chaperone Hsp90, which regulates the form and function of diverse client proteins, potentiates resistance to the azoles in C. albicans and in the model yeast Saccharomyces cerevisiae. Genetic studies in S. cerevisiae revealed that Hsp90's role in azole resistance is to enable crucial cellular responses to the membrane stress exerted by azoles via the client protein calcineurin. Here, we demonstrate that Hsp90 governs cellular circuitry required for resistance to the only new class of antifungals to reach the clinic in decades, the echinocandins, which inhibit biosynthesis of a critical component of the fungal cell wall. Pharmacological or genetic impairment of Hsp90 function reduced tolerance of C. albicans laboratory strains and resistance of clinical isolates to the echinocandins and created a fungicidal combination. Compromising calcineurin function phenocopied compromising Hsp90 function. We established that calcineurin is an Hsp90 client protein in C. albicans: reciprocal co-immunoprecipitation validated physical interaction; Hsp90 inhibition blocked calcineurin activation; and calcineurin levels were depleted upon genetic reduction of Hsp90. The downstream effector of calcineurin, Crz1, played a partial role in mediating calcineurin-dependent stress responses activated by echinocandins. Hsp90's role in echinocandin resistance has therapeutic potential given that genetic compromise of C. albicans HSP90 expression enhanced the efficacy of an echinocandin in a murine model of disseminated candidiasis. Our results identify the first Hsp90 client protein in C. albicans, establish an entirely

  20. Hsp90: Friends, clients and natural foes.

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    Verma, Sharad; Goyal, Sukriti; Jamal, Salma; Singh, Aditi; Grover, Abhinav

    2016-08-01

    Hsp90, a homodimeric ATPase, is responsible for the correct folding of a number of newly synthesized polypeptides in addition to the correct folding of denatured/misfolded client proteins. It requires several co-chaperones and other partner proteins for chaperone activity. Due to the involvement of Hsp90-dependent client proteins in a variety of oncogenic signaling pathways, Hsp90 inhibition has emerged as one of the leading strategies for anticancer chemotherapeutics. Most of Hsp90 inhibitors blocks the N terminal ATP binding pocket and prevents the conformational changes which are essential for the loading of co-chaperones and client proteins. Several other inhibitors have also been reported which disrupt chaperone cycle in ways other than binding to N terminal ATP binding pocket. The Hsp90 inhibition is associated with heat shock response, mediated by HSF-1, to overcome the loss of Hsp90 and sustain cell survival. This review is an attempt to give an over view of all the important players of chaperone cycle.

  1. Terazosin activates Pgk1 and Hsp90 to promote stress resistance.

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    Chen, Xinping; Zhao, Chunyue; Li, Xiaolong; Wang, Tao; Li, Yizhou; Cao, Cheng; Ding, Yuehe; Dong, Mengqiu; Finci, Lorenzo; Wang, Jia-Huai; Li, Xiaoyu; Liu, Lei

    2015-01-01

    Drugs that can protect against organ damage are urgently needed, especially for diseases such as sepsis and brain stroke. We discovered that terazosin (TZ), a widely marketed α1-adrenergic receptor antagonist, alleviated organ damage and improved survival in rodent models of stroke and sepsis. Through combined studies of enzymology and X-ray crystallography, we discovered that TZ binds a new target, phosphoglycerate kinase 1 (Pgk1), and activates its enzymatic activity, probably through 2,4-diamino-6,7-dimethoxyisoquinoline's ability to promote ATP release from Pgk1. Mechanistically, the ATP generated from Pgk1 may enhance the chaperone activity of Hsp90, an ATPase known to associate with Pgk1. Upon activation, Hsp90 promotes multistress resistance. Our studies demonstrate that TZ has a new protein target, Pgk1, and reveal its corresponding biological effect. As a clinical drug, TZ may be quickly translated into treatments for diseases including stroke and sepsis.

  2. Hsp90 as a "Chaperone" of the Epigenome: Insights and Opportunities for Cancer Therapy.

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    Isaacs, Jennifer S

    2016-01-01

    The cellular functions of Hsp90 have historically been attributed to its ability to chaperone client proteins involved in signal transduction. Although numerous stimuli and the signaling cascades they activate contribute to cancer progression, many of these pathways ultimately require transcriptional effectors to elicit tumor-promoting effects. Despite this obvious connection, the majority of studies evaluating Hsp90 function in malignancy have focused upon its regulation of cytosolic client proteins, and particularly members of receptor and/or kinase families. However, in recent years, Hsp90 has emerged as a pivotal orchestrator of nuclear events. Discovery of an expanding repertoire of Hsp90 clients has illuminated a vital role for Hsp90 in overseeing nuclear events and influencing gene transcription. Hence, this chapter will cast a spotlight upon several regulatory themes involving Hsp90-dependent nuclear functions. Highlighted topics include a summary of chaperone-dependent regulation of key transcription factors (TFs) and epigenetic effectors in malignancy, as well as a discussion of how the complex interplay among a subset of these TFs and epigenetic regulators may generate feed-forward loops that further support cancer progression. This chapter will also highlight less recognized indirect mechanisms whereby Hsp90-supported signaling may impinge upon epigenetic regulation. Finally, the relevance of these nuclear events is discussed within the framework of Hsp90's capacity to enable phenotypic variation and drug resistance. These newly acquired insights expanding our understanding of Hsp90 function support the collective notion that nuclear clients are major beneficiaries of Hsp90 action, and their impairment is likely responsible for many of the anticancer effects elicited by Hsp90-targeted approaches.

  3. Targeting Hsp90-Cdc37: a promising therapeutic strategy by inhibiting Hsp90 chaperone function.

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    Wang, Lei; Li, Li; Gu, Kai; Xu, Xiao-Li; You, Qi-Dong; Sun, Hao-Peng

    2016-05-27

    The Hsp90 chaperone protein regulates the folding, maturation and stability of a wide variety of oncoproteins. In recent years, many Hsp90 inhibitors have entered into the clinical trials while all of them target ATPase showing similar binding capacity and kinds of side-effects so that none have reached to the market. During the regulation progress, numerous protein-protein interactions (PPI) such as Hsp90 and client proteins or cochaperones are involved. With the Hsp90-cochaperones PPI networks being more and more clear, many cancerous proteins have been reported to be tightly correlated to Hsp90-cochaperones PPI. Among them, Hsp90-Cdc37 PPI has been widely reported to associate with numerous protein kinases, making it a novel target for the treatment of cancers. In this paper, we briefly review the strategies and modulators targeting Hsp90-Cdc37 complex including direct and indirect regulation mechanism. Through these discussions we expect to present inspirations for new insights into an alternative way to inhibit Hsp90 chaperone function.

  4. Paralog-selective Hsp90 inhibitors define tumor-specific regulation of Her2

    Science.gov (United States)

    Patel, Pallav D.; Yan, Pengrong; Seidler, Paul M.; Patel, Hardik J.; Sun, Weilin; Yang, Chenghua; Que, Nanette S.; Taldone, Tony; Finotti, Paola; Stephani, Ralph A.; Gewirth, Daniel T.; Chiosis, Gabriela

    2014-01-01

    Although the Hsp90 chaperone family, comprised in humans of four paralogs, Hsp90α, Hsp90β, Grp94 and Trap-1, has important roles in malignancy, the contribution of each paralog to the cancer phenotype is poorly understood. This is in large part because reagents to study paralog-specific functions in cancer cells have been unavailable. Here we combine compound library screening with structural and computational analyses to identify purine-based chemical tools that are specific for Hsp90 paralogs. We show that Grp94 selectivity is due to the insertion of these compounds into a new allosteric pocket. We use these tools to demonstrate that cancer cells use individual Hsp90 paralogs to regulate a client protein in a tumor-specific manner and in response to proteome alterations. Finally, we provide new mechanistic evidence explaining why selective Grp94 inhibition is particularly efficacious in certain breast cancers. PMID:23995768

  5. The association of SNPs in Hsp90β gene 5' flanking region with thermo tolerance traits and tissue mRNA expression in two chicken breeds.

    Science.gov (United States)

    Chen, Zhuo-Yu; Gan, Jian-Kang; Xiao, Xiong; Jiang, Li-Yan; Zhang, Xi-Quan; Luo, Qing-Bin

    2013-09-01

    Thermo stress induces heat shock proteins (HSPs) expression and HSP90 family is one of them that has been reported to involve in cellular protection against heat stress. But whether there is any association of genetic variation in the Hsp90β gene in chicken with thermo tolerance is still unknown. Direct sequencing was used to detect possible SNPs in Hsp90β gene 5' flanking region in 3 chicken breeds (n = 663). Six mutations, among which 2 SNPs were chosen and genotypes were analyzed with PCR-RFLP method, were found in Hsp90β gene in these 3 chicken breeds. Association analysis indicated that SNP of C.-141G>A in the 5' flanking region of the Hsp90β gene in chicken had some effect on thermo tolerance traits, which may be a potential molecular marker of thermo tolerance, and the genotype GG was the thermo tolerance genotype. Hsp90β gene mRNA expression in different tissues detected by quantitative real-time PCR assay were demonstrated to be tissue dependent, implying that different tissues have distinct sensibilities to thermo stress. Besides, it was shown time specific and varieties differences. The expression of Hsp90β mRNA in Lingshan chickens in some tissues including heart, liver, brain and spleen were significantly higher or lower than that of White Recessive Rock (WRR). In this study, we presume that these mutations could be used in marker assisted selection for anti-heat stress chickens in our breeding program, and WRR were vulnerable to tropical thermo stress whereas Lingshan chickens were well adapted.

  6. Targeting Hsp90 in Non-Cancerous Maladies.

    Science.gov (United States)

    Woodford, Mark R; Dunn, Diana M; Ciciarelli, Joseph G; Beebe, Kristin; Neckers, Len; Mollapour, Mehdi

    2016-01-01

    Heat shock protein-90 (Hsp90) is a molecular chaperone critical to the folding, stability and activity of over 200 client proteins including many responsible for tumor initiation, progression and metastasis. Hsp90 chaperone function is linked to its ATPase activity and Hsp90 inhibitors interfere with this activity, thereby making Hsp90 an attractive target for cancer therapy. Also post-translational modification (PTM) and co-chaperone proteins modulate Hsp90 function, providing additional targets for secondary inhibition. Recent reports have shown that pathogens utilize both their own Hsp90 and that of their host for the propagation of infectious elements. In this review we will summarize our current knowledge of Hsp90 structure and function in both the pathogen and the host. We will focus on the role of Hsp90 in viral and parasitic diseases and the potential beneficial application of Hsp90 inhibitors alone and in combination with disease-specific inhibitors.

  7. Molecular characterization, gene expression and transcriptional regulation of cytosolic HSP90 genes in the flatfish Senegalese sole (Solea senegalensis Kaup).

    Science.gov (United States)

    Manchado, Manuel; Salas-Leiton, Emilio; Infante, Carlos; Ponce, Marian; Asensio, Esther; Crespo, Aniela; Zuasti, Eugenia; Cañavate, José Pedro

    2008-06-15

    HSP90 proteins are chaperones that play a pivotal role in controlling multiple regulatory pathways such as stress defense, hormone signalling, cell cycle control, cell proliferation and differentiation, and apoptosis. In this study, two cDNAs encoding for cytosolic HSP90, referred to as HSP90AA and HSP90AB, have been sequenced. Main features and sequence identities with other fish and mammals are described. Phylogenetic analysis grouped both genes into two separate clusters with their fish and mammalian counterparts. Expression profiles during larval development and in juvenile tissues were analyzed using a real-time PCR approach. In juvenile fish, HSP90AB was constitutively expressed with lower transcript levels in skeletal muscle. In contrast, HSP90AA was mainly expressed in heart, skeletal muscle and skin. During metamorphosis, HSP90AB mRNA levels did not change whereas HSP90AA transcripts decreased significantly at the beginning of metamorphosis with the lowest mRNA levels at the metamorphosis climax. Due to the role of thyroid hormones (THs) on sole metamorphosis, the transcriptional regulation of HSP90 genes by THs was evaluated. Larvae exposed to the goitrogen thiourea (TU) exhibited higher HSP90AA mRNA levels than untreated control. Moreover, adding exogenous T4 hormone to TU-treated larvae restored the steady-state levels with respect to the untreated control. Unlike HSP90AA, the transcript levels of HSP90AB did not vary under any treatments. The response of both HSP90 genes to thermal stress in post-metamorphic individuals was also studied. A heat shock treatment (+7.9 degrees C for 1 h) rapidly activated HSP90AA (but not HSP90AB) transcription, reaching a peak after 30 min and declining expression levels progressively in the following 24 h. No significant changes in HSP90AA or HSP90AB transcript levels after a cold shock (-10 degrees C for 1 h) were observed. Overall, these results demonstrate that HSP90AA transcription is down-regulated by THs and up

  8. Reconstructing the Hsp90/Tau Machine.

    Science.gov (United States)

    Jinwal, Umesh K; Koren, John; Dickey, Chad A

    2013-01-01

    Imbalanced protein load within cells is a critical aspect for most diseases of aging. In particular, the accumulation of proteins into neurotoxic aggregates is a common thread for a host of neurodegenerative diseases. Recent work demonstrates that age-related changes to the cellular chaperone repertoire contributes to abnormal buildup of the microtubule-associated protein tau that accumulates in a group of diseases termed tauopathies, the most common being Alzheimer's disease (AD). The Hsp90 co-chaperone repertoire has diverse effects on tau stability; some co-chaperones stabilize tau while others facilitate its clearance. We propose that each of these proteins may be novel therapeutic targets. While targeting Hsp90 directly may be deleterious at the organismal level, perhaps targeting individual co-chaperone activities will be more tolerable.

  9. Molecular mechanisms of canalization: Hsp90 and beyond

    Indian Academy of Sciences (India)

    Neeraj Salathia; Christine Queitsch

    2007-04-01

    The Hsp90 chaperone machine facilitates the maturation of a diverse set of ‘client’ proteins. Many of these Hsp90 clients are essential nodes in signal transduction pathways and regulatory circuits, accounting for the important role Hsp90 plays in organismal development and responses to the environment. Recent findings suggest a broader impact of the chaperone on phenotype: fully functional Hsp90 canalizes wild-type phenotypes by suppressing underlying genetic and epigenetic variation. This variation can be expressed upon challenging the Hsp90 machinery by environmental stress, genetic or pharmaceutical targeting of Hsp90. The existence of Hsp90-buffered genetic and epigenetic variation together with plausible release mechanisms has wide-ranging implication for phenotype and possibly evolutionary processes. Here, we discuss the role of Hsp90 in canalization and organismal plasticity, and highlight important questions for future experimental inquiry.

  10. Cytosolic HSP90 Cochaperones HOP and FKBP Interact with Freshly Synthesized Chloroplast Preproteins of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Christine Fellerer; Regina Schweiger; Katharina Sch(o)ngruber; Jürgen Soll; Serena Schwenkert

    2011-01-01

    Most chloroplast and mitochondrial proteins are synthesized in the cytosol of the plant cell and have to be imported into the organelles post-translationally.Molecular chaperones play an important role in preventing protein aggregation of freshly translated preproteins and assist in maintaining the preproteins in an import competent state.Preproteins can associate with HSPT0,HSP90,and 14-3-3 proteins in the cytosol.In this study,we analyzed a large set of wheat germ-translated chloroplast preproteins with respect to their chaperone binding.Our results demonstrate that the formation of distinct 14-3-3 or HSP90 containing preprotein complexes is a common feature in post-translational protein transport in addition to preproteins that seem to interact solely with HSP70.We were able to identify a diverse and extensive class of preproteins as HSP90 substrates,thus providing a tool for the investigation of HSP90 client protein association.The analyses of chimeric HSP90 and 14-3-3 binding preproteins with exchanged transit peptides indicate an involvement of both the transit peptide and the mature part of the proteins,in HSP90 binding.We identified two partner components of the HSP90 cycle,which were present in the preprotein containing high-molecular-weight complexes,the HSP70/HSP90 organizing protein HOP,as well as the immunophilin FKBP73.The results establish chloroplast preproteins as a general class of HSP90 client proteins in plants using HOP and FKBP as novel cochaperones.

  11. Effect of Benzo[a]pyrene or/and Heat on Levels of HSP70 and HSP90 β in Mice Brain%苯并[a]芘和高温及其联合作用对小鼠脑组织HSP70和HSP90 β水平的影响

    Institute of Scientific and Technical Information of China (English)

    涂白杰; 邬堂春; 贺涵贞

    2004-01-01

    目的研究苯并[a]芘(BaP)、高温及其联合作用对小鼠脑组织热应激蛋白70(HSP70)与热应激蛋白90β(HSP90 β)表达的影响.方法将56只昆明种小鼠随机分为7组(每组8只), 即空白对照组、溶剂对照组、低剂量BaP单独染毒组、高剂量BaP单独染毒组、单独高温处理组、高温处理+低剂量BaP染毒组、高温处理+高剂量BaP染毒组.低、高剂量BaP染毒分别给予BaP 0.5mg/kg和5mg/kg,用植物油作溶剂,每周4次腹腔注射,溶剂对照组用植物油作平行处理,空白对照组不做处理.高温处理为每周4次,每次41.5~42.0℃处理2 h.实验8周后取各组小鼠脑组织制作混合匀浆,Westernblot法检测HSP70和HSP 90 β水平.结果 HSP70在高温单独作用、低剂量BaP单独作用、高温与低剂量BaP联合作用下表达明显升高.HSP90 β仅在高温与低剂量BaP联合作用及高温与高剂量BaP联合作用下表达升高.结论不同的热应激蛋白在不同条件下对高温、BaP染毒等有害因素对脑组织的损害起保护和标志作用.

  12. Could Upregulated Hsp70 Protein Compensate for the Hsp90-Silence-Induced Cell Death in Glioma Cells?

    Directory of Open Access Journals (Sweden)

    Chinmay Munje

    2014-01-01

    Full Text Available The molecular chaperone heat shock protein 90 alpha (Hsp90α has been recognized in various tumours including glioma. This pilot study using a proteomic approach analyses the downstream effects of Hsp90 inhibition using 17-allylamino-17-demethoxygeldanamycin (17AAG and a short hairpin RNA (shRNA oligonucleotide targeting hsp90α (shhsp90α in the U87-MG glioma cell line. Preliminary data coupled with bioinformatic analysis identified several known and unknown Hsp90 client proteins that demonstrated a change in their protein expression after Hsp90 inhibition, signifying an alteration in the canonical pathways of cell cycle progression, apoptosis, cell invasion, angiogenesis, and metastasis. Members of the glycolysis pathway were upregulated, demonstrating increased dependency on glycolysis for energy source by the treated glioma cells. Upregulated proteins also include Hsp70 and members of its family such as Hsp27 and gp96, thereby suggesting the role of Hsp90 co-chaperones in compensating for Hsp90 function after Hsp90 inhibition. Considering Hsp70’s role in antiapoptosis, it was postulated that a combination therapy involving a multitarget approach could be carried out. Consequently inhibition of both Hsp90 and Hsp70 in U87-MG glioma cells resulted in 60% cell death indicating the importance of combination therapy for glioma therapeutics.

  13. The HSP90 inhibitor alvespimycin enhances the potency of telomerase inhibition by imetelstat in human osteosarcoma

    OpenAIRE

    Hu, Yafang; Bobb, Daniel; He, Jianping; Hill, D. Ashley; Dome, Jeffrey S.

    2015-01-01

    The unsatisfactory outcomes for osteosarcoma necessitate novel therapeutic strategies. This study evaluated the effect of the telomerase inhibitor imetelstat in pre-clinical models of human osteosarcoma. Because the chaperone molecule HSP90 facilitates the assembly of telomerase protein, the ability of the HSP90 inhibitor alvespimycin to potentiate the effect of the telomerase inhibitor was assessed. The effect of single or combined treatment with imetelstat and alvespimycin on long-term grow...

  14. Little effect of HSP90 inhibition on the quantitative wing traits variation in Drosophila melanogaster.

    Science.gov (United States)

    Takahashi, Kazuo H

    2017-02-01

    Drosophila wings have been a model system to study the effect of HSP90 on quantitative trait variation. The effect of HSP90 inhibition on environmental buffering of wing morphology varies among studies while the genetic buffering effect of it was examined in only one study and was not detected. Variable results so far might show that the genetic background influences the environmental and genetic buffering effect of HSP90. In the previous studies, the number of the genetic backgrounds used is limited. To examine the effect of HSP90 inhibition with a larger number of genetic backgrounds than the previous studies, 20 wild-type strains of Drosophila melanogaster were used in this study. Here I investigated the effect of HSP90 inhibition on the environmental buffering of wing shape and size by assessing within-individual and among-individual variations, and as a result, I found little or very weak effects on environmental and genetic buffering. The current results suggest that the role of HSP90 as a global regulator of environmental and genetic buffering is limited at least in quantitative traits.

  15. The crystal structure of the Hsp90 co-chaperone Cpr7 from Saccharomyces cerevisiae.

    Science.gov (United States)

    Qiu, Yu; Ge, Qiangqiang; Wang, Mingxing; Lv, Hui; Ebrahimi, Mohammad; Niu, Liwen; Teng, Maikun; Li, Xu

    2017-02-09

    The versatility of Hsp90 can be attributed to the variety of co-chaperone proteins that modulate the role of Hsp90 in many cellular processes. As a co-chaperone of Hsp90, Cpr7 is essential for accelerating the cell growth in an Hsp90-containing trimeric complex. Here, we report the crystal structure of Cpr7 at a resolution of 1.8Å. It consists of an N-terminal PPI domain and a C-terminal TPR domain, and exhibits a U-shape conformation. Our studies revealed the aggregation state of Cpr7 in solution and the interaction properties between Cpr7 and the MEEVD sequence from the C-terminus of Hsp90. In addition, the structure and sequence analysis between Cpr7 and homologues revealed the structure basis both for the function differences between Cpr6 and Cpr7 and the functional complements between Cns1 and Cpr7. Our studies facilitate the understanding of Cpr7 and provide decent insights into the molecular mechanisms of the Hsp90 co-chaperone pathway.

  16. Characterisation of the Plasmodium falciparum Hsp70-Hsp90 organising protein (PfHop).

    Science.gov (United States)

    Gitau, Grace W; Mandal, Pradipta; Blatch, Gregory L; Przyborski, Jude; Shonhai, Addmore

    2012-03-01

    Malaria is caused by Plasmodium species, whose transmission to vertebrate hosts is facilitated by mosquito vectors. The transition from the cold blooded mosquito vector to the host represents physiological stress to the parasite, and additionally malaria blood stage infection is characterised by intense fever periods. In recent years, it has become clear that heat shock proteins play an essential role during the parasite's life cycle. Plasmodium falciparum expresses two prominent heat shock proteins: heat shock protein 70 (PfHsp70) and heat shock protein 90 (PfHsp90). Both of these proteins have been implicated in the development and pathogenesis of malaria. In eukaryotes, Hsp70 and Hsp90 proteins are functionally linked by an essential adaptor protein known as the Hsp70-Hsp90 organising protein (Hop). In this study, recombinant P. falciparum Hop (PfHop) was heterologously produced in E. coli and purified by nickel affinity chromatography. Using specific anti-PfHop antisera, the expression and localisation of PfHop in P. falciparum was investigated. PfHop was shown to co-localise with PfHsp70 and PfHsp90 in parasites at the trophozoite stage. Gel filtration and co-immunoprecipitation experiments suggested that PfHop was present in a complex together with PfHsp70 and PfHsp90. The association of PfHop with both PfHsp70 and PfHsp90 suggests that this protein may mediate the functional interaction between the two chaperones.

  17. The evolutionary capacitor HSP90 buffers the regulatory effects of mammalian endogenous retroviruses.

    Science.gov (United States)

    Hummel, Barbara; Hansen, Erik C; Yoveva, Aneliya; Aprile-Garcia, Fernando; Hussong, Rebecca; Sawarkar, Ritwick

    2017-03-01

    Understanding how genotypes are linked to phenotypes is important in biomedical and evolutionary studies. The chaperone heat-shock protein 90 (HSP90) buffers genetic variation by stabilizing proteins with variant sequences, thereby uncoupling phenotypes from genotypes. Here we report an unexpected role of HSP90 in buffering cis-regulatory variation affecting gene expression. By using the tripartite-motif-containing 28 (TRIM28; also known as KAP1)-mediated epigenetic pathway, HSP90 represses the regulatory influence of endogenous retroviruses (ERVs) on neighboring genes that are critical for mouse development. Our data based on natural variations in the mouse genome show that genes respond to HSP90 inhibition in a manner dependent on their genomic location with regard to strain-specific ERV-insertion sites. The evolutionary-capacitor function of HSP90 may thus have facilitated the exaptation of ERVs as key modifiers of gene expression and morphological diversification. Our findings add a new regulatory layer through which HSP90 uncouples phenotypic outcomes from individual genotypes.

  18. HSP90 promotes Burkitt lymphoma cell survival by maintaining tonic B-cell receptor signaling.

    Science.gov (United States)

    Walter, Roland; Pan, Kuan-Ting; Doebele, Carmen; Comoglio, Federico; Tomska, Katarzyna; Bohnenberger, Hanibal; Young, Ryan M; Jacobs, Laura; Keller, Ulrich; Bönig, Halvard; Engelke, Michael; Rosenwald, Andreas; Urlaub, Henning; Staudt, Louis M; Serve, Hubert; Zenz, Thorsten; Oellerich, Thomas

    2017-02-02

    Burkitt lymphoma (BL) is an aggressive B-cell neoplasm that is currently treated by intensive chemotherapy in combination with anti-CD20 antibodies. Because of their toxicity, current treatment regimens are often not suitable for elderly patients or for patients in developing countries where BL is endemic. Targeted therapies for BL are therefore needed. In this study, we performed a compound screen in 17 BL cell lines to identify small molecule inhibitors affecting cell survival. We found that inhibitors of heat shock protein 90 (HSP90) induced apoptosis in BL cells in vitro at concentrations that did not affect normal B cells. By global proteomic and phosphoproteomic profiling, we show that, in BL, HSP90 inhibition compromises the activity of the pivotal B-cell antigen receptor (BCR)-proximal effector spleen tyrosine kinase (SYK), which we identified as an HSP90 client protein. Consistently, expression of constitutively active TEL-SYK counteracted the apoptotic effect of HSP90 inhibition. Together, our results demonstrate that HSP90 inhibition impairs BL cell survival by interfering with tonic BCR signaling, thus providing a molecular rationale for the use of HSP90 inhibitors in the treatment of BL.

  19. Development of Noviomimetics as C-Terminal Hsp90 Inhibitors.

    Science.gov (United States)

    Anyika, Mercy; McMullen, Mason; Forsberg, Leah K; Dobrowsky, Rick T; Blagg, Brian S J

    2016-01-14

    KU-32 and KU-596 are novobiocin-derived, C-terminal heat shock protein 90 (Hsp90) modulators that induce Hsp70 levels and manifest neuroprotective activity. However, the synthetically complex noviose sugar requires 10 steps to prepare, which makes translational development difficult. In this study, we developed a series of "noviomimetic" analogues of KU-596, which contain noviose surrogates that can be easily prepared, while maintaining the ability to induce Hsp70 levels. Both sugar and sugar analogues were designed, synthesized, and evaluated in a luciferase reporter assay, which identified compound 37, a benzyl containing noviomimetic, as the most potent inducer of Hsp70.

  20. Mps1 Mediated Phosphorylation of Hsp90 Confers Renal Cell Carcinoma Sensitivity and Selectivity to Hsp90 Inhibitors

    Directory of Open Access Journals (Sweden)

    Mark R. Woodford

    2016-02-01

    Full Text Available The molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity and selectivity toward Hsp90 inhibitors; however, the molecular mechanism underlying this phenotype remains undefined. We report that the mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in the amino-domain of Hsp90. This, in turn, regulates chaperone function by reducing Hsp90 ATPase activity while fostering Hsp90 association with kinase clients, including Mps1. Phosphorylation of Hsp90 is also essential for the mitotic checkpoint because it confers Mps1 stability and activity. We identified Cdc14 as the phosphatase that dephosphorylates Hsp90 and disrupts its interaction with Mps1. This causes Mps1 degradation, thus providing a mechanism for its inactivation. Finally, Hsp90 phosphorylation sensitizes cells to its inhibitors, and elevated Mps1 levels confer renal cell carcinoma selectivity to Hsp90 drugs. Mps1 expression level can potentially serve as a predictive indicator of tumor response to Hsp90 inhibitors.

  1. Hsp90 governs dispersion and drug resistance of fungal biofilms.

    Directory of Open Access Journals (Sweden)

    Nicole Robbins

    2011-09-01

    Full Text Available Fungal biofilms are a major cause of human mortality and are recalcitrant to most treatments due to intrinsic drug resistance. These complex communities of multiple cell types form on indwelling medical devices and their eradication often requires surgical removal of infected devices. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. We previously established that in the leading human fungal pathogen, Candida albicans, Hsp90 enables the emergence and maintenance of drug resistance in planktonic conditions by stabilizing the protein phosphatase calcineurin and MAPK Mkc1. Hsp90 also regulates temperature-dependent C. albicans morphogenesis through repression of cAMP-PKA signalling. Here we demonstrate that genetic depletion of Hsp90 reduced C. albicans biofilm growth and maturation in vitro and impaired dispersal of biofilm cells. Further, compromising Hsp90 function in vitro abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal drugs, the azoles. Depletion of Hsp90 led to reduction of calcineurin and Mkc1 in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 levels led to a marked decrease in matrix glucan levels, providing a compelling mechanism through which Hsp90 might regulate biofilm azole resistance. Impairment of Hsp90 function genetically or pharmacologically transformed fluconazole from ineffectual to highly effective in eradicating biofilms in a rat venous catheter infection model. Finally, inhibition of Hsp90 reduced resistance of biofilms of the most lethal mould, Aspergillus fumigatus, to the newest class of antifungals to reach the clinic, the echinocandins. Thus, we establish a novel mechanism regulating biofilm drug resistance and dispersion and that targeting Hsp90 provides a much-needed strategy for improving

  2. Terazosin activated Pgk1 and Hsp90 to promote stress resistance

    Science.gov (United States)

    Chen, Xinping; Zhao, Chunyue; Li, Xiaolong; Wang, Tao; Li, Yizhou; Cao, Cheng; Ding, Yuehe; Dong, Mengqiu; Finci, Lorenzo; Wang, Jia-huai; Li, Xiaoyu; Liu, Lei

    2015-01-01

    Drugs that can protect against organ damage are urgently needed, especially for diseases such as sepsis and brain stroke. We have discovered that terazosin (TZ), a widely marketed alpha1-adrenergic receptor agonist, alleviated organ damage and improved survival in rodent models of stroke and sepsis. Through combined studies of enzymology and X-ray crystallography, we have discovered that TZ binds to a novel target, phosphoglycerate kinase 1 (Pgk1) and activates its enzymatic activity, probably through 1,3-diamino-6,7-dimethoxyisoquinoline's ability to promote ATP release from Pgk1. Mechanistically, the ATP generated from Pgk1 may enhance the chaperone activity of Hsp90, an ATPase known to associate with Pgk1. Upon activation, Hsp90 promotes multi-stress resistance. Our studies have demonstrated that TZ has a novel protein target, Pgk1, and has revealed its corresponding biological effect. As a clinical drug, TZ may be quickly translated into treatment of devastating diseases including stroke and sepsis. PMID:25383758

  3. Hsp90 regulation of fibroblast activation in pulmonary fibrosis

    Science.gov (United States)

    Sontake, Vishwaraj; Wang, Yunguan; Kasam, Rajesh K.; Sinner, Debora; Reddy, Geereddy B.; Naren, Anjaparavanda P.; McCormack, Francis X.; Jegga, Anil G.; Madala, Satish K.

    2017-01-01

    Idiopathic pulmonary fibrosis (IPF) is a severe fibrotic lung disease associated with fibroblast activation that includes excessive proliferation, tissue invasiveness, myofibroblast transformation, and extracellular matrix (ECM) production. To identify inhibitors that can attenuate fibroblast activation, we queried IPF gene signatures against a library of small-molecule-induced gene-expression profiles and identified Hsp90 inhibitors as potential therapeutic agents that can suppress fibroblast activation in IPF. Although Hsp90 is a molecular chaperone that regulates multiple processes involved in fibroblast activation, it has not been previously proposed as a molecular target in IPF. Here, we found elevated Hsp90 staining in lung biopsies of patients with IPF. Notably, fibroblasts isolated from fibrotic lesions showed heightened Hsp90 ATPase activity compared with normal fibroblasts. 17-N-allylamino-17-demethoxygeldanamycin (17-AAG), a small-molecule inhibitor of Hsp90 ATPase activity, attenuated fibroblast activation and also TGF-β–driven effects on fibroblast to myofibroblast transformation. The loss of the Hsp90AB, but not the Hsp90AA isoform, resulted in reduced fibroblast proliferation, myofibroblast transformation, and ECM production. Finally, in vivo therapy with 17-AAG attenuated progression of established and ongoing fibrosis in a mouse model of pulmonary fibrosis, suggesting that targeting Hsp90 represents an effective strategy for the treatment of fibrotic lung disease. PMID:28239659

  4. New phagotrophic euglenoid species (new genus Decastava; Scytomonas saepesedens; Entosiphon oblongum), Hsp90 introns, and putative euglenoid Hsp90 pre-mRNA insertional editing.

    Science.gov (United States)

    Cavalier-Smith, Thomas; Chao, Ema E; Vickerman, Keith

    2016-10-01

    We describe three new phagotrophic euglenoid species by light microscopy and 18S rDNA and Hsp90 sequencing: Scytomonas saepesedens; Decastava edaphica; Entosiphon oblongum. We studied Scytomonas and Decastava ultrastructure. Scytomonas saepesedens feeds when sessile with actively beating cilium, and has five pellicular strips with flush joints and Calycimonas-like microtubule-supported cytopharynx. Decastava, sister to Keelungia forming new clade Decastavida on 18S rDNA trees, has 10 broad strips with cusp-like joints, not bifurcate ridges like Ploeotia and Serpenomonas (phylogenetically and cytologically distinct genera), and Serpenomonas-like feeding apparatus (8-9 unreinforced microtubule pairs loop from dorsal jaw support to cytostome). Hsp90 and 18S rDNA trees group Scytomonas with Petalomonas and show Entosiphon as the earliest euglenoid branch. Basal euglenoids have rigid longitudinal strips; derived clade Spirocuta has spiral often slideable strips. Decastava Hsp90 genes have introns. Decastava/Entosiphon Hsp90 frameshifts imply insertional RNA editing. Petalomonas is too heterogeneous in pellicle structure for one genus; we retain Scytomonas (sometimes lumped with it) and segregate four former Petalomonas as new genus Biundula with pellicle cross section showing 2-8 smooth undulations and typified by Biundula (=Petalomonas) sphagnophila comb. n. Our taxon-rich site-heterogeneous rDNA trees confirm that Heteronema is excessively heterogeneous; therefore we establish new genus Teloprocta for Heteronema scaphurum.

  5. Structure, Function and Regulation of the Hsp90 Machinery

    Directory of Open Access Journals (Sweden)

    Jing Li

    2013-06-01

    Full Text Available Heat shock protein 90 (Hsp90 is an ATP-dependent molecular chaperone which is essential in eukaryotes. It is required for the activation and stabilization of a wide variety of client proteins and many of them are involved in important cellular pathways. Since Hsp90 affects numerous physiological processes such as signal transduction, intracellular transport, and protein degradation, it became an interesting target for cancer therapy. Structurally, Hsp90 is a flexible dimeric protein composed of three different domains which adopt structurally distinct conformations. ATP binding triggers directionality in these conformational changes and leads to a more compact state. To achieve its function, Hsp90 works together with a large group of cofactors, termed co-chaperones. Co-chaperones form defined binary or ternary complexes with Hsp90, which facilitate the maturation of client proteins. In addition, posttranslational modifications of Hsp90, such as phosphorylation and acetylation, provide another level of regulation. They influence the conformational cycle, co-chaperone interaction, and inter-domain communications. In this review, we discuss the recent progress made in understanding the Hsp90 machinery.

  6. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1.

    Science.gov (United States)

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-11-03

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp.

  7. Exploring in vitro and in vivo Hsp90 inhibitors activity against human protozoan parasites.

    Science.gov (United States)

    Giannini, Giuseppe; Battistuzzi, Gianfranco

    2015-02-01

    A set of compounds, previously selected as potent Hsp90α inhibitors, has been studied on a panel of human parasites. 5-Aryl-3,4-isoxazolediamide derivatives (1) were active against two protozoa, Trypanosoma brucei rhodesiense and Plasmodium falciparum, with a good tolerability toward cytotoxicity on non-malignant L6 rat myoblast cell line, unlike the 1,5-diaryl,4-carboxamides-1,2,3-triazole derivatives (2) which, while showing a single-digit nM range activity against the same protozoa, were also highly cytotoxic on L6 cells. In a subsequent in vivo study, two isoxazolediamide derivatives, 1a and 1b, were very efficacious on the sleeping sickness-causing agent with a clear parasitaemia during treatment. These data, however, showed that not all protozoa are sensitive to Hsp90 inhibitors, as well as not all Hsp90 inhibitors are equally active on parasites.

  8. The ribosomal biogenesis protein Utp21 interacts with Hsp90 and has differing requirements for Hsp90-associated proteins.

    Directory of Open Access Journals (Sweden)

    Victoria R Tenge

    Full Text Available The molecular chaperone Hsp90 buffers the effects of genetic variation by assisting the stabilization and folding of multiple clients critical for cell signaling and growth. We identified an interaction of Hsp90 and associated proteins with the essential nucleolar protein, Utp21, part of a large complex required for biogenesis of the small ribosomal subunit. The utp21-S602F mutation, which causes minor defects in otherwise wild-type yeast, exhibited severe or lethal growth defects when combined with mutations in Hsp90 or co-chaperones. WT Utp21 and Utp21-S602F exhibited similar interactions with Hsp90, and steady-state levels of WT Utp21 were reduced upon Hsp90 mutation or inhibition. Mutations in the human homolog of UTP21, WDR36, have been associated with adult-onset primary open-angle glaucoma, a leading cause of blindness worldwide. Three different mutant forms of Utp21 analogous to glaucoma-associated WDR36 mutations exhibit reduced levels in yeast cells expressing mutations in Hsp90 or associated chaperones, suggesting that Hsp90 and co-chaperones buffer the effects of those mutations.

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

    Directory of Open Access Journals (Sweden)

    Christos A. Papadimitriou

    2012-09-01

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

  10. Modeling signal propagation mechanisms and ligand-based conformational dynamics of the Hsp90 molecular chaperone full-length dimer.

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    Giulia Morra

    2009-03-01

    Full Text Available Hsp90 is a molecular chaperone essential for protein folding and activation in normal homeostasis and stress response. ATP binding and hydrolysis facilitate Hsp90 conformational changes required for client activation. Hsp90 plays an important role in disease states, particularly in cancer, where chaperoning of the mutated and overexpressed oncoproteins is important for function. Recent studies have illuminated mechanisms related to the chaperone function. However, an atomic resolution view of Hsp90 conformational dynamics, determined by the presence of different binding partners, is critical to define communication pathways between remote residues in different domains intimately affecting the chaperone cycle. Here, we present a computational analysis of signal propagation and long-range communication pathways in Hsp90. We carried out molecular dynamics simulations of the full-length Hsp90 dimer, combined with essential dynamics, correlation analysis, and a signal propagation model. All-atom MD simulations with timescales of 70 ns have been performed for complexes with the natural substrates ATP and ADP and for the unliganded dimer. We elucidate the mechanisms of signal propagation and determine "hot spots" involved in interdomain communication pathways from the nucleotide-binding site to the C-terminal domain interface. A comprehensive computational analysis of the Hsp90 communication pathways and dynamics at atomic resolution has revealed the role of the nucleotide in effecting conformational changes, elucidating the mechanisms of signal propagation. Functionally important residues and secondary structure elements emerge as effective mediators of communication between the nucleotide-binding site and the C-terminal interface. Furthermore, we show that specific interdomain signal propagation pathways may be activated as a function of the ligand. Our results support a "conformational selection model" of the Hsp90 mechanism, whereby the protein may

  11. C-terminal sequences of hsp70 and hsp90 as non-specific anchors for tetratricopeptide repeat (TPR) proteins.

    Science.gov (United States)

    Ramsey, Andrew J; Russell, Lance C; Chinkers, Michael

    2009-10-12

    Steroid-hormone-receptor maturation is a multi-step process that involves several TPR (tetratricopeptide repeat) proteins that bind to the maturation complex via the C-termini of hsp70 (heat-shock protein 70) and hsp90 (heat-shock protein 90). We produced a random T7 peptide library to investigate the roles played by the C-termini of the two heat-shock proteins in the TPR-hsp interactions. Surprisingly, phages with the MEEVD sequence, found at the C-terminus of hsp90, were not recovered from our biopanning experiments. However, two groups of phages were isolated that bound relatively tightly to HsPP5 (Homo sapiens protein phosphatase 5) TPR. Multiple copies of phages with a C-terminal sequence of LFG were isolated. These phages bound specifically to the TPR domain of HsPP5, although mutation studies produced no evidence that they bound to the domain's hsp90-binding groove. However, the most abundant family obtained in the initial screen had an aspartate residue at the C-terminus. Two members of this family with a C-terminal sequence of VD appeared to bind with approximately the same affinity as the hsp90 C-12 control. A second generation pseudo-random phage library produced a large number of phages with an LD C-terminus. These sequences acted as hsp70 analogues and had relatively low affinities for hsp90-specific TPR domains. Unfortunately, we failed to identify residues near hsp90's C-terminus that impart binding specificity to individual hsp90-TPR interactions. The results suggest that the C-terminal sequences of hsp70 and hsp90 act primarily as non-specific anchors for TPR proteins.

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

    Science.gov (United States)

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

    2009-06-01

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

  13. The HSP90 inhibitor alvespimycin enhances the potency of telomerase inhibition by imetelstat in human osteosarcoma.

    Science.gov (United States)

    Hu, Yafang; Bobb, Daniel; He, Jianping; Hill, D Ashley; Dome, Jeffrey S

    2015-01-01

    The unsatisfactory outcomes for osteosarcoma necessitate novel therapeutic strategies. This study evaluated the effect of the telomerase inhibitor imetelstat in pre-clinical models of human osteosarcoma. Because the chaperone molecule HSP90 facilitates the assembly of telomerase protein, the ability of the HSP90 inhibitor alvespimycin to potentiate the effect of the telomerase inhibitor was assessed. The effect of single or combined treatment with imetelstat and alvespimycin on long-term growth was assessed in osteosarcoma cell lines (143B, HOS and MG-63) and xenografts derived from 143B cells. Results indicated that imetelstat as a single agent inhibited telomerase activity, induced telomere shortening, and inhibited growth in all 3 osteosarcoma cell lines, though the bulk cell cultures did not undergo growth arrest. Combined treatment with imetelstat and alvespimycin resulted in diminished telomerase activity and shorter telomeres compared to either agent alone as well as higher levels of γH2AX and cleaved caspase-3, indicative of increased DNA damage and apoptosis. With dual telomerase and HSP90 inhibition, complete growth arrest of bulk cell cultures was achieved. In xenograft models, all 3 treatment groups significantly inhibited tumor growth compared with the placebo-treated control group, with the greatest effect seen in the combined treatment group (imetelstat, p = 0.045, alvespimycin, p = 0.034; combined treatment, p = 0.004). In conclusion, HSP90 inhibition enhanced the effect of telomerase inhibition in pre-clinical models of osteosarcoma. Dual targeting of telomerase and HSP90 warrants further investigation as a therapeutic strategy.

  14. Research Progress of HSP90 in Aquatic Animals and Plants%HSP90及其在水生动植物中的研究进展

    Institute of Scientific and Technical Information of China (English)

    周向红

    2011-01-01

    The classification, structure and transcription regulation of HSP90s were briefly reviewed. Special attention was paid to inducing expression and physiological function of HSP90s in aquatic animals and plants.%简要介绍了HSP90的分类、结构和转录调控,重点讨论了HSP90在水产动植物中的诱导表达与生理功能.

  15. A CNS-permeable Hsp90 inhibitor rescues synaptic dysfunction and memory loss in APP-overexpressing Alzheimer’s mouse model via an HSF1-mediated mechanism

    Science.gov (United States)

    Wang, Bin; Liu, Yu; Huang, Lianyan; Chen, Jianjun; Li, Jing jing; Wang, Ruishan; Kim, Eunhee; Justicia, Carles; Sakata, Kazuko; Chen, Hao; Planas, Anna; Ostrom, Rennolds S; Li, Wei; Yang, Guang; McDonald, Michael P.; Chen, Ruihong; Heck, Detlef; Liao, Francesca-Fang

    2016-01-01

    Induction of neuroprotective heat-shock proteins via pharmacological Hsp90 inhibitors is currently being investigated as a potential treatment for neurodegenerative diseases. Two major hurdles for therapeutic use of Hsp90 inhibitors are systemic toxicity and limited CNS permeability. We demonstrate here that chronic treatment with a proprietary Hsp90 inhibitor compound (OS47720) not only elicits a heat shock-like response, but also offers synaptic protection in symptomatic Tg2576 mice, a model of Alzheimer’s disease (AD), without noticeable systemic toxicity. Despite a short half-life of OS47720 in mouse brain, a single intraperitoneal injection induces rapid and long-lasting (> 3 d) nuclear activation of the heat shock factor, HSF1. Mechanistic study indicates that the remedial effects of OS47720 depend upon HSF1 activation and the subsequent HSF-1-mediated transcriptional events on synaptic genes. Taken together, this work reveals a novel role of HSF1 in synaptic function and memory, which likely occurs through modulation of the synaptic transcriptome. PMID:27457810

  16. The soluble recombinant Neisseria meningitidis adhesin NadA(Δ351-405) stimulates human monocytes by binding to extracellular Hsp90.

    Science.gov (United States)

    Cecchini, Paola; Tavano, Regina; Polverino de Laureto, Patrizia; Franzoso, Susanna; Mazzon, Cristina; Montanari, Paolo; Papini, Emanuele

    2011-01-01

    The adhesin NadA favors cell adhesion/invasion by hypervirulent Neisseria meningitidis B (MenB). Its recombinant form NadA(Δ351-405,) devoid of the outer membrane domain, is an immunogenic candidate for an anti-MenB vaccine able to stimulate monocytes, macrophages and dendritic cells. In this study we investigated the molecular mechanism of NadA(Δ351-405) cellular effects in monocytes. We show that NadA(Δ351-405) (against which we obtained polyclonal antibodies in rabbits), binds to hsp90, but not to other extracellular homologous heat shock proteins grp94 and hsp70, in vitro and on the surface of monocytes, in a temperature dependent way. Pre-incubation of monocytes with the MenB soluble adhesin interfered with the binding of anti-hsp90 and anti-hsp70 antibodies to hsp90 and hsp70 at 37°C, a condition in which specific cell-binding occurs, but not at 0°C, a condition in which specific cell-binding is very diminished. Conversely, pre-incubation of monocytes with anti-hsp90 and anti-hsp70 antibodies did not affected NadA(Δ351-405) cell binding in any temperature condition, indicating that it associates to another receptor on their plasma membrane and then laterally diffuses to encounter hsp90. Consistently, polymixin B interfered with NadA(Δ351-405) /hsp90 association, abrogated the decrease of anti-hsp90 antibodies binding to the cell surface due to NadA(Δ351-405) and inhibited adhesin-induced cytokine/chemokine secretion without affecting monocyte-adhesin binding. Co-stimulation of monocytes with anti-hsp90 antibodies and NadA(Δ351-405) determined a stronger but polymixin B insensitive cell activation. This indicated that the formation of a recombinant NadA/hsp90/hsp70 complex, although essential for full monocyte stimulation, can be replaced by anti-hsp90 antibody/hsp90 binding. Finally, the activation of monocytes by NadA(Δ351-405) alone or in the presence of anti-hsp90 antibodies were both inhibited by neutralizing anti-TLR4 antibodies, but not by

  17. Hsp90: A New Player in DNA Repair?

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    Rosa Pennisi

    2015-10-01

    Full Text Available Heat shock protein 90 (Hsp90 is an evolutionary conserved molecular chaperone that, together with Hsp70 and co-chaperones makes up the Hsp90 chaperone machinery, stabilizing and activating more than 200 proteins, involved in protein homeostasis (i.e., proteostasis, transcriptional regulation, chromatin remodeling, and DNA repair. Cells respond to DNA damage by activating complex DNA damage response (DDR pathways that include: (i cell cycle arrest; (ii transcriptional and post-translational activation of a subset of genes, including those associated with DNA repair; and (iii triggering of programmed cell death. The efficacy of the DDR pathways is influenced by the nuclear levels of DNA repair proteins, which are regulated by balancing between protein synthesis and degradation as well as by nuclear import and export. The inability to respond properly to either DNA damage or to DNA repair leads to genetic instability, which in turn may enhance the rate of cancer development. Multiple components of the DNA double strand breaks repair machinery, including BRCA1, BRCA2, CHK1, DNA-PKcs, FANCA, and the MRE11/RAD50/NBN complex, have been described to be client proteins of Hsp90, which acts as a regulator of the diverse DDR pathways. Inhibition of Hsp90 actions leads to the altered localization and stabilization of DDR proteins after DNA damage and may represent a cell-specific and tumor-selective radiosensibilizer. Here, the role of Hsp90-dependent molecular mechanisms involved in cancer onset and in the maintenance of the genome integrity is discussed and highlighted.

  18. Nuclear HSP90 and HSP70 in COPD patients treated with formoterol or formoterol and corticosteroids

    Directory of Open Access Journals (Sweden)

    Holownia A

    2009-12-01

    Full Text Available Abstract Objective Heat shock proteins assist cellular protein folding and are required for the normal activity of steroid receptors. In this study we assessed nuclear HSP90 and HSP70 proteins and mRNA levels in cells isolated from induced sputum of chronic obstructive pulmonary disease patients treated for 4 weeks with formoterol (F or formoterol+budesonide (F/ICS. Methods Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates using qRT-PCR. Results Both HSP90 and HSP70 protein levels were higher in the F/ICS-treated patients in comparison with the F-treated group (by 31%, P Conclusions It is possible that increased nuclear heat shock proteins may play a role in the attenuation of the response to glucocorticoids in COPD patients.

  19. Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2

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    Sanne H. Olesen

    2015-01-01

    Full Text Available The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein–protein interaction (PPI inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2 did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM, while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.

  20. Stability of the human Hsp90-p50Cdc37 chaperone complex against nucleotides and Hsp90 inhibitors, and the influence of phosphorylation by casein kinase 2.

    Science.gov (United States)

    Olesen, Sanne H; Ingles, Donna J; Zhu, Jin-Yi; Martin, Mathew P; Betzi, Stephane; Georg, Gunda I; Tash, Joseph S; Schönbrunn, Ernst

    2015-01-19

    The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein-protein interaction (PPI) inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2) did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM), while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.

  1. Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2

    Science.gov (United States)

    Olesen, Sanne H.; Ingles, Donna J.; Zhu, Jin-Yi; Martin, Mathew P.; Betzi, Stephane; Georg, Gunda I.; Tash, Joseph S.; Schönbrunn, Ernst

    2015-01-01

    The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein-protein interaction (PPI) inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in-vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2) did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM), while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands. PMID:25608045

  2. The HSP90 Inhibitor Ganetespib Radiosensitizes Human Lung Adenocarcinoma Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Casal, Roberto; Bhattacharya, Chitralekha [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Medicine, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Epperly, Michael W. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Radiation Oncology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Basse, Per H. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Immunology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Wang, Hong [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Biostatistics, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Wang, Xinhui [Harvard Medical School, Harvard University, 25 Shattuck Street, Boston, MA 02115 (United States); Proia, David A. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Greenberger, Joel S. [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Radiation Oncology, The University of Pittsburgh, Pittsburgh, PA 15213 (United States); Socinski, Mark A.; Levina, Vera, E-mail: levinav@upmc.edu [The University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213 (United States); Department of Medicine, The University of Pittsburgh, Pittsburgh, PA 15213 (United States)

    2015-05-22

    The molecular chaperone HSP90 is involved in stabilization and function of multiple client proteins, many of which represent important oncogenic drivers in NSCLC. Utilization of HSP90 inhibitors as radiosensitizing agents is a promising approach. The antitumor activity of ganetespib, HSP90 inhibitor, was evaluated in human lung adenocarcinoma (AC) cells for its ability to potentiate the effects of IR treatment in both in vitro and in vivo. The cytotoxic effects of ganetespib included; G2/M cell cycle arrest, inhibition of DNA repair, apoptosis induction, and promotion of senescence. All of these antitumor effects were both concentration- and time-dependent. Both pretreatment and post-radiation treatment with ganetespib at low nanomolar concentrations induced radiosensitization in lung AC cells in vitro. Ganetespib may impart radiosensitization through multiple mechanisms: such as down regulation of the PI3K/Akt pathway; diminished DNA repair capacity and promotion of cellular senescence. In vivo, ganetespib reduced growth of T2821 tumor xenografts in mice and sensitized tumors to IR. Tumor irradiation led to dramatic upregulation of β-catenin expression in tumor tissues, an effect that was mitigated in T2821 xenografts when ganetespib was combined with IR treatments. These data highlight the promise of combining ganetespib with IR therapies in the treatment of AC lung tumors.

  3. Treatment of Arabidopsis thaliana seeds with an HSP90 inhibitor increases plant resistance

    Science.gov (United States)

    Kozeko, Liudmyla

    2016-07-01

    Resistance of plants to unfavourable conditions is an important feature to use them as an autotrophic link of Life Support Systems in space exploration missions. It significantly depends on basic and stress-induced levels of heat shock proteins (HSP) in cells. It is known that HSP90 can bind and maintain heat shock transcription factors (HSF) as a monomer that lacks DNA binding activity and thereby regulate HSP expression. Modulation of activity of the HSP synthesis and resistance by HSP90 in plants is not well investigated. The objective of this study was to determine how treatment of seeds with an HSP90 inhibitor affects environmental responsiveness in Arabidopsis thaliana. Seed treatment with geldanamycin (GDA) was used to reduce HSP90 function. The affect of space flight stressors was simulated by gamma-irradiation and thermal upshift. Two series of experiments were carried out: 1) exposure of dry seeds to gamma-irradiation (1 kGy, ^{60}Co); 2) heat shock of seedlings. It was shown that GDA treatment of seeds stimulated the seedling growth after seed irradiation. It also increased both the basic thermotolerance (45°C for 45 min) and induced thermotolerance (45°C for 1,5-2,5 h after pretreatment at 37°C for 2 h) in seedlings. In addition, seed treatment with GDA had a prolonged effect on the HSP70 production in seedlings under normal and stressful conditions. It shows that the stimulatory effects of GDA may be caused by induction of HSP70 synthesis. The obtained data demonstrate that pre-treatment of seeds with GDA before planting allows inducing the stress resistance at least at early growth stages of plants.

  4. Molecular Dynamics Simulations Reveal the Mechanisms of Allosteric Activation of Hsp90 by Designed Ligands.

    Science.gov (United States)

    Vettoretti, Gerolamo; Moroni, Elisabetta; Sattin, Sara; Tao, Jiahui; Agard, David A; Bernardi, Anna; Colombo, Giorgio

    2016-04-01

    Controlling biochemical pathways through chemically designed modulators may provide novel opportunities to develop therapeutic drugs and chemical tools. The underlying challenge is to design new molecular entities able to act as allosteric chemical switches that selectively turn on/off functions by modulating the conformational dynamics of their target protein. We examine the origins of the stimulation of ATPase and closure kinetics in the molecular chaperone Hsp90 by allosteric modulators through atomistic molecular dynamics (MD) simulations and analysis of protein-ligand interactions. In particular, we focus on the cross-talk between allosteric ligands and protein conformations and its effect on the dynamic properties of the chaperone's active state. We examine the impact of different allosteric modulators on the stability, structural and internal dynamics properties of Hsp90 closed state. A critical aspect of this study is the development of a quantitative model that correlates Hsp90 activation to the presence of a certain compound, making use of information on the dynamic adaptation of protein conformations to the presence of the ligand, which allows to capture conformational states relevant in the activation process. We discuss the implications of considering the conformational dialogue between allosteric ligands and protein conformations for the design of new functional modulators.

  5. Hsp70/Hsp90 organising protein (hop): beyond interactions with chaperones and prion proteins.

    Science.gov (United States)

    Baindur-Hudson, Swati; Edkins, Adrienne L; Blatch, Gregory L

    2015-01-01

    The Hsp70/Hsp90 organising protein (Hop), also known as stress-inducible protein 1 (STI1), has received considerable attention for diverse cellular functions in both healthy and diseased states. There is extensive evidence that intracellular Hop is a co-chaperone of the major chaperones Hsp70 and Hsp90, playing an important role in the productive folding of Hsp90 client proteins. Consequently, Hop is implicated in a number of key signalling pathways, including aberrant pathways leading to cancer. However, Hop is also secreted and it is now well established that Hop also serves as a receptor for the prion protein, PrP(C). The intracellular and extracellular forms of Hop most likely represent two different isoforms, although the molecular determinants of these divergent functions are yet to be identified. There is also a growing body of research that reports the involvement of Hop in cellular activities that appear independent of either chaperones or PrP(C). While Hop has been shown to have various cellular functions, its biological function remains elusive. However, recent knockout studies in mammals suggest that Hop has an important role in embryonic development. This review provides a critical overview of the latest molecular, cellular and biological research on Hop, critically evaluating its function in healthy systems and how this function is adapted in diseases states.

  6. Thermodynamic Analysis of the Geldanamycin-Hsp90 Interaction in a Whole Cell Lysate Using a Mass Spectrometry-Based Proteomics Approach

    Science.gov (United States)

    Xu, Yingrong; Wallace, M. Ariel Geer; Fitzgerald, Michael C.

    2016-10-01

    Geldanamycin is a natural product with well-established and potent anti-cancer activities. Heat shock protein 90 (Hsp90) is the known target of geldanamycin, which directly binds to Hsp90's N-terminal ATP binding domain and inhibits Hsp90's ATPase activity. The affinity of geldanamycin for Hsp90 has been measured in multiple studies. However, there have been large discrepancies between the reported dissociation constants (i.e., Kd values), which have ranged from low nanomolar to micromolar. Here the stability of proteins from rates of oxidation (SPROX) technique was used in combination with an isobaric mass tagging strategy to measure the binding affinity of geldanamycin to unpurified Hsp90 in an MCF-7 cell lysate. The Kd values determined here were dependent on how long geldanamycin was equilibrated with the lysate prior to SPROX analysis. The Kd values determined using equilibration times of 0.5 and 24 h were 1 and 0.03 μM, respectively. These Kd values, which are similar to those previously reported in a geldanamycin-Hsp90 binding study that involved the use of a fluorescently labeled geldanamycin analogue, establish that the slow-tight binding behavior previously observed for the fluorescently labeled geldanamycin analogue is not an artifact of the fluorescent label, but rather an inherent property of the geldanamycin-Hsp90 binding interaction. The slow-tight binding property of this complex may be related to time-dependent conformational changes in Hsp90 and/or to time-dependent chemical changes in geldanamycin, both of which have been previously proposed to explain the slow-tight binding behavior of the geldanamycin-Hsp90 complex.

  7. Hsp70 and the Cochaperone StiA (Hop) Orchestrate Hsp90-Mediated Caspofungin Tolerance in Aspergillus fumigatus.

    Science.gov (United States)

    Lamoth, Frédéric; Juvvadi, Praveen R; Soderblom, Erik J; Moseley, M Arthur; Steinbach, William J

    2015-08-01

    Aspergillus fumigatus is the primary etiologic agent of invasive aspergillosis (IA), a major cause of death among immunosuppressed patients. Echinocandins (e.g., caspofungin) are increasingly used as second-line therapy for IA, but their activity is only fungistatic. Heat shock protein 90 (Hsp90) was previously shown to trigger tolerance to caspofungin and the paradoxical effect (i.e., decreased efficacy of caspofungin at higher concentrations). Here, we demonstrate the key role of another molecular chaperone, Hsp70, in governing the stress response to caspofungin via Hsp90 and their cochaperone Hop/Sti1 (StiA in A. fumigatus). Mutation of the StiA-interacting domain of Hsp70 (C-terminal EELD motif) impaired thermal adaptation and caspofungin tolerance with loss of the caspofungin paradoxical effect. Impaired Hsp90 function and increased susceptibility to caspofungin were also observed following pharmacologic inhibition of the C-terminal domain of Hsp70 by pifithrin-μ or after stiA deletion, further supporting the links among Hsp70, StiA, and Hsp90 in governing caspofungin tolerance. StiA was not required for the physical interaction between Hsp70 and Hsp90 but had distinct roles in the regulation of their function in caspofungin and heat stress responses. In conclusion, this study deciphering the physical and functional interactions of the Hsp70-StiA-Hsp90 complex provided new insights into the mechanisms of tolerance to caspofungin in A. fumigatus and revealed a key C-terminal motif of Hsp70, which can be targeted by specific inhibitors, such as pifithrin-μ, to enhance the antifungal activity of caspofungin against A. fumigatus.

  8. Targeting Plasmodium falciparum Hsp90: Towards Reversing Antimalarial Resistance

    Directory of Open Access Journals (Sweden)

    Dea Shahinas

    2013-02-01

    Full Text Available Malaria continues to exact a great human toll in tropical settings. Antimalarial resistance is rife and the parasite inexorably develops mechanisms to outwit our best drugs, including the now first-line choice, artesunate. Novel strategies to circumvent resistance are needed. Here we detail drug development focusing on heat shock protein 90 and its central role as a chaperone. A growing body of evidence supports the role for Hsp90 inhibitors as adjunctive drugs able to restore susceptibility to traditionally efficacious compounds like chloroquine.

  9. Spatio-temporal regulation of Hsp90-ligand complex leads to immune activation.

    Directory of Open Access Journals (Sweden)

    Yasuaki eTamura

    2016-05-01

    Full Text Available Hsp90 is the most abundant cytosolic HSP and is known to act as a molecular chaperone. We found that an Hsp90-cancer antigen peptide complex was efficiently cross-presented by human monocyte-derived dendritic cells and induced peptide-specific cytotoxic T lymphocytes. Furthermore, we observed that the internalized Hsp90-peptide complex was strictly sorted to the Rab5+, EEA1+ static early endosome and the Hsp90-chaperoned peptide was processed and bound to MHC class I molecules through a endosome-recycling pathway. We also found that extracellular Hsp90 complexed with CpG-A or self-DNA stimulates production of a large amount of IFN-α from pDCs via static early endosome targeting. Thus, extracellular Hsp90 can target the antigen or nucleic acid to a static early endosome by spatio-temporal regulation. Moreover, we showed that Hsp90 associates with and delivers TLR7/9 from the ER to early endosomes for ligand recognition. Hsp90 inhibitor, geldanamycin derivative inhibited the Hsp90 association with TLR7/9, resulting in inhibition IFN-α production, leading to improvement of SLE symptoms. Interstingly, we observed that serum Hsp90 is clearly increased in patients with active SLE compared with that in patients with inactive disease. Serum Hsp90 detected in SLE patients binds to self-DNA and/or anti-DNA Ab, thus leading to stimulation of pDCs to produce IFN-α. Thus, Hsp90 plays a crucial role in the pathogenesis of SLE and that an Hsp90 inhibitor will therefore provide a new therapeutic approach to SLE and other nucleic acid-related autoimmune diseases. We will discuss how spatio-temporal regulation of Hsp90-ligand complexes within antigen-presenting cells affects the innate immunity and adaptive immunity.

  10. Genome-scale co-evolutionary inference identifies functions and clients of bacterial Hsp90.

    Directory of Open Access Journals (Sweden)

    Maximilian O Press

    Full Text Available The molecular chaperone Hsp90 is essential in eukaryotes, in which it facilitates the folding of developmental regulators and signal transduction proteins known as Hsp90 clients. In contrast, Hsp90 is not essential in bacteria, and a broad characterization of its molecular and organismal function is lacking. To enable such characterization, we used a genome-scale phylogenetic analysis to identify genes that co-evolve with bacterial Hsp90. We find that genes whose gain and loss were coordinated with Hsp90 throughout bacterial evolution tended to function in flagellar assembly, chemotaxis, and bacterial secretion, suggesting that Hsp90 may aid assembly of protein complexes. To add to the limited set of known bacterial Hsp90 clients, we further developed a statistical method to predict putative clients. We validated our predictions by demonstrating that the flagellar protein FliN and the chemotaxis kinase CheA behaved as Hsp90 clients in Escherichia coli, confirming the predicted role of Hsp90 in chemotaxis and flagellar assembly. Furthermore, normal Hsp90 function is important for wild-type motility and/or chemotaxis in E. coli. This novel function of bacterial Hsp90 agreed with our subsequent finding that Hsp90 is associated with a preference for multiple habitats and may therefore face a complex selection regime. Taken together, our results reveal previously unknown functions of bacterial Hsp90 and open avenues for future experimental exploration by implicating Hsp90 in the assembly of membrane protein complexes and adaptation to novel environments.

  11. Interactions of p60, a mediator of progesterone receptor assembly, with heat shock proteins hsp90 and hsp70

    DEFF Research Database (Denmark)

    Chen, S; Prapapanich, V; Rimerman, R A;

    1996-01-01

    mature PR complexes. In the present study we observe that a monoclonal antibody specific for p60 can, on the one hand, inhibit formation of mature PR complexes containing heat shock protein 90 (hsp90), p23, and immunophilins and, on the other, enhance recovery of early PR complexes containing hsp70...

  12. DsHsp90 Is Involved in the Early Response of Dunaliella salina to Environmental Stress

    Directory of Open Access Journals (Sweden)

    Si-Jia Wang

    2012-06-01

    Full Text Available Heat shock protein 90 (Hsp90 is a molecular chaperone highly conserved across the species from prokaryotes to eukaryotes. Hsp90 is essential for cell viability under all growth conditions and is proposed to act as a hub of the signaling network and protein homeostasis of the eukaryotic cells. By interacting with various client proteins, Hsp90 is involved in diverse physiological processes such as signal transduction, cell mobility, heat shock response and osmotic stress response. In this research, we cloned the dshsp90 gene encoding a polypeptide composed of 696 amino acids from the halotolerant unicellular green algae Dunaliella salina. Sequence alignment indicated that DsHsp90 belonged to the cytosolic Hsp90A family. Further biophysical and biochemical studies of the recombinant protein revealed that DsHsp90 possessed ATPase activity and existed as a dimer with similar percentages of secondary structures to those well-studied Hsp90As. Analysis of the nucleotide sequence of the cloned genomic DNA fragment indicated that dshsp90 contained 21 exons interrupted by 20 introns, which is much more complicated than the other plant hsp90 genes. The promoter region of dshsp90 contained putative cis-acting stress responsive elements and binding sites of transcriptional factors that respond to heat shock and salt stress. Further experimental research confirmed that dshsp90 was upregulated quickly by heat and salt shock in the D. salina cells. These findings suggested that dshsp90 might serve as a component of the early response system of the D. salina cells against environmental stresses.

  13. Identification and Characterization of a Bursaphelenchus xylophilus (Aphelenchida: Aphelenchoididae Thermotolerance-Related Gene: Bx-HSP90

    Directory of Open Access Journals (Sweden)

    Danlei Li

    2012-07-01

    Full Text Available Temperatures directly influence the distribution and intensity of pine wilt disease caused by the pine wood nematode, Bursaphelenchus xylophilus. To date, however, little is known about the causation and mechanism of this influence. The molecular chaperone HSP90 is a key component that contributes to survival in the abiotic stress response. In this study, we investigated the relationship between the survival of B. xylophilus and the functionality of the HSP90 gene. Bx-HSP90 was cloned from a suppression subtractive hybridization library. In situ mRNA hybridization showed that Bx-HSP90 was constitutively expressed in response to all of the temperatures tested, and RT-PCR indicated that all of the temperatures could induce Bx-HSP90 transcription, with the highest transcript level detected at 30 °C. The suppression of the Bx-HSP90 transcript by RNA interference led to a 25% reduction in the number of nematodes at 30 °C after 44 h. Sharp declines in the survival of the RNAi-treated nematodes were observed after 8 days at 25 °C, 48 h at 30 °C and 24 h at 35 °C. Both heat shock and the knockdown of Bx-HSP90 hindered the growth of the B. xylophilus populations. The results indicate that Bx-HSP90 is essential for the survival of B. xylophilus, confirming the thermoregulatory function of the gene, and delineate the timeframe and temperature range within which the gene function occurs.

  14. HDAC6 regulates androgen receptor hypersensitivity and nuclear localization via modulating Hsp90 acetylation in castration-resistant prostate cancer.

    Science.gov (United States)

    Ai, Junkui; Wang, Yujuan; Dar, Javid A; Liu, June; Liu, Lingqi; Nelson, Joel B; Wang, Zhou

    2009-12-01

    The development of castration-resistant prostate cancer (PCa) requires that under castration conditions, the androgen receptor (AR) remains active and thus nuclear. Heat shock protein 90 (Hsp90) plays a key role in androgen-induced and -independent nuclear localization and activation of AR. Histone deacetylase 6 (HDAC6) is implicated, but has not been proven, in regulating AR activity via modulating Hsp90 acetylation. Here, we report that knockdown of HDAC6 in C4-2 cells using short hairpin RNA impaired ligand-independent nuclear localization of endogenous AR and inhibited PSA expression and cell growth in the absence or presence of dihydrotestosterone (DHT). The dose-response curve of DHT-stimulated C4-2 colony formation was shifted by shHDAC6 such that approximately 10-fold higher concentration of DHT is required, indicating a requirement for HDAC6 in AR hypersensitivity. HDAC6 knockdown also inhibited C4-2 xenograft tumor establishment in castrated, but not in testes-intact, nude mice. Studies using HDAC6-deficient mouse embryonic fibroblasts cells showed that inhibition of AR nuclear localization by HDAC6 knockdown can be largely alleviated by expressing a deacetylation mimic Hsp90 mutant. Taken together, our studies suggest that HDAC6 regulates AR hypersensitivity and nuclear localization, mainly via modulating HSP90 acetylation. Targeting HDAC6 alone or in combination with other therapeutic approaches is a promising new strategy for prevention and/or treatment of castration-resistant PCa.

  15. Cloning and Expression of a Cytosolic HSP90 Gene in Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Zhengyi Liu

    2014-01-01

    Full Text Available Heat shock protein 90 (HSP90, a highly conserved molecular chaperone, plays essential roles in folding, keeping structural integrity, and regulating the subset of cytosolic proteins. We cloned the cDNA of Chlorella vulgaris HSP90 (named CvHSP90 by combining homology cloning with rapid amplification of cDNA ends (RACE. Sequence analysis indicated that CvHSP90 is a cytosolic member of the HSP90 family. Quantitative RT-PCR was applied to determine the expression level of messenger RNA (mRNA in CvHSP90 under different stress conditions. C. vulgaris was kept in different temperatures (5–45°C for 1 h. The mRNA expression level of CvHSP90 increased with temperature from 5 to 10°C, went further from 35 to 40°C, and reached the maximum at 40°C. On the other hand, for C. vulgaris kept at 35°C for different durations, the mRNA expression level of CvHSP90 increased gradually and reached the peak at 7 h and then declined progressively. In addition, the expression level of CvHSP90 at 40 or 45 in salinity (‰ was almost fourfold of that at 25 in salinity (‰ for 2 h. Therefore, CvHSP90 may be a potential biomarker to monitor environment changes.

  16. Functional Divergence of Hsp90 Genetic Interactions in Biofilm and Planktonic Cellular States.

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    Stephanie Diezmann

    Full Text Available Candida albicans is among the most prevalent opportunistic fungal pathogens. Its capacity to cause life-threatening bloodstream infections is associated with the ability to form biofilms, which are intrinsically drug resistant reservoirs for dispersal. A key regulator of biofilm drug resistance and dispersal is the molecular chaperone Hsp90, which stabilizes many signal transducers. We previously identified 226 C. albicans Hsp90 genetic interactors under planktonic conditions, of which 56 are involved in transcriptional regulation. Six of these transcriptional regulators have previously been implicated in biofilm formation, suggesting that Hsp90 genetic interactions identified in planktonic conditions may have functional significance in biofilms. Here, we explored the relationship between Hsp90 and five of these transcription factor genetic interactors: BCR1, MIG1, TEC1, TUP1, and UPC2. We deleted each transcription factor gene in an Hsp90 conditional expression strain, and assessed biofilm formation and morphogenesis. Strikingly, depletion of Hsp90 conferred no additional biofilm defect in the mutants. An interaction was observed in which deletion of BCR1 enhanced filamentation upon reduction of Hsp90 levels. Further, although Hsp90 modulates expression of TEC1, TUP1, and UPC2 in planktonic conditions, it has no impact in biofilms. Lastly, we probed for physical interactions between Hsp90 and Tup1, whose WD40 domain suggests that it might interact with Hsp90 directly. Hsp90 and Tup1 formed a stable complex, independent of temperature or developmental state. Our results illuminate a physical interaction between Hsp90 and a key transcriptional regulator of filamentation and biofilm formation, and suggest that Hsp90 has distinct genetic interactions in planktonic and biofilm cellular states.

  17. RNAi knockdown of Hop (Hsp70/Hsp90 organising protein) decreases invasion via MMP-2 down regulation.

    LENUS (Irish Health Repository)

    Walsh, Naomi

    2011-07-28

    We previously identified Hop as over expressed in invasive pancreatic cancer cell lines and malignant tissues of pancreatic cancer patients, suggesting an important role for Hop in the biology of invasive pancreatic cancer. Hop is a co-chaperone protein that binds to both Hsp70\\/Hsp90. We hypothesised that by targeting Hop, signalling pathways modulating invasion and client protein stabilisation involving Hsp90-dependent complexes may be altered. In this study, we show that Hop knockdown by small interfering (si)RNA reduces the invasion of pancreatic cancer cells, resulting in decreased expression of the downstream target gene, matrix metalloproteinases-2 (MMP-2). Hop in conditioned media co-immunoprecipitates with MMP-2, implicating a possible extracellular function for Hop. Knockdown of Hop expression also reduced expression levels of Hsp90 client proteins, HER2, Bcr-Abl, c-MET and v-Src. Furthermore, Hop is strongly expressed in high grade PanINs compared to lower PanIN grades, displaying differential localisation in invasive ductal pancreatic cancer, indicating that the localisation of Hop is an important factor in pancreatic tumours. Our data suggests that the attenuation of Hop expression inactivates key signal transduction proteins which may decrease the invasiveness of pancreatic cancer cells possibly through the modulation of Hsp90 activity. Therefore, targeting Hop in pancreatic cancer may constitute a viable strategy for targeted cancer therapy.

  18. Repercussion of mitochondria deformity induced by anti-Hsp90 drug 17AAG in human tumor cells

    KAUST Repository

    Vishal, Chaturvedi

    2011-06-07

    Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects on tumor cell mitochondria were largely unknown. Here, we show that Hsp90 inhibition with 17AAG first affects mitochondrial integrity in different human tumor cells, neuroblastoma, cervical cancer and glial cells. Using human neuroblastoma tumor cells, we found the early effects associated with a change in mitochondrial membrane potential, elongation and engorgement of mitochondria because of an increased matrix vacuolization. These effects are specific to Hsp90 inhibition as other chemotherapeutic drugs did not induce similar mitochondrial deformity. Further, the effects are independent of oxidative damage and cytoarchitecture destabilization since cytoskeletal disruptors and mitochondrial metabolic inhibitors also do not induce similar deformity induced by 17AAG. The 1D PAGE LC MS/ MS mitochondrial proteome analysis of 17AAG treated human neuroblastoma cells showed a loss of 61% proteins from membrane, metabolic, chaperone and ribonucleoprotein families. About 31 unmapped protein IDs were identified from proteolytic processing map using Swiss-Prot accession number, and converted to the matching gene name searching the ExPASy proteomics server. Our studies display that Hsp90 inhibition effects at first embark on mitochondria of tumor cells and compromise mitochondrial integrity. the author(s), publisher and licensee Libertas Academica Ltd.

  19. RNAi knockdown of Hop (Hsp70/Hsp90 organising protein) decreases invasion via MMP-2 down regulation.

    Science.gov (United States)

    Walsh, Naomi; Larkin, AnneMarie; Swan, Niall; Conlon, Kevin; Dowling, Paul; McDermott, Ray; Clynes, Martin

    2011-07-28

    We previously identified Hop as over expressed in invasive pancreatic cancer cell lines and malignant tissues of pancreatic cancer patients, suggesting an important role for Hop in the biology of invasive pancreatic cancer. Hop is a co-chaperone protein that binds to both Hsp70/Hsp90. We hypothesised that by targeting Hop, signalling pathways modulating invasion and client protein stabilisation involving Hsp90-dependent complexes may be altered. In this study, we show that Hop knockdown by small interfering (si)RNA reduces the invasion of pancreatic cancer cells, resulting in decreased expression of the downstream target gene, matrix metalloproteinases-2 (MMP-2). Hop in conditioned media co-immunoprecipitates with MMP-2, implicating a possible extracellular function for Hop. Knockdown of Hop expression also reduced expression levels of Hsp90 client proteins, HER2, Bcr-Abl, c-MET and v-Src. Furthermore, Hop is strongly expressed in high grade PanINs compared to lower PanIN grades, displaying differential localisation in invasive ductal pancreatic cancer, indicating that the localisation of Hop is an important factor in pancreatic tumours. Our data suggests that the attenuation of Hop expression inactivates key signal transduction proteins which may decrease the invasiveness of pancreatic cancer cells possibly through the modulation of Hsp90 activity. Therefore, targeting Hop in pancreatic cancer may constitute a viable strategy for targeted cancer therapy.

  20. Whey protein hydrolysate enhances HSP90 but does not alter HSP60 and HSP25 in skeletal muscle of rats.

    Directory of Open Access Journals (Sweden)

    Carolina Soares Moura

    Full Text Available Whey protein hydrolysate (WPH intake has shown to increase HSP70 expression. The aim of the present study was to investigate whether WPH intake would also influences HSP90, HSP60 and HSP25 expression, as well as associated parameters. Forty-eight male Wistar rats were divided into sedentary (unstressed and exercised (stressed groups, and were fed with three different sources of protein: whey protein (WP, whey protein hydrolysate (WPH and casein (CAS as a control, based on the AIN93G diet for 3 weeks. WPH intake increased HSP90 expression in both sedentary and exercised animals compared to WP or CAS, however no alteration was found from exercise or diet to HSP60 or HSP25. Co-chaperone Aha1 and p-HSF1 were also increased in the exercised animals fed with WPH in comparison with WP or CAS, consistent with enhanced HSP90 expression. VEGF and p-AKT were increased in the WPH exercised group. No alteration was found in BCKDH, PI3-Kinase (p85, GFAT, OGT or PGC for diet or exercise. The antioxidant system GPx, catalase and SOD showed different responses to diet and exercise. The data indicate that WPH intake enhanced factors related to cell survival, such as HSP90 and VEGF, but does not alter HSP60 or HSP25 in rat skeletal muscle.

  1. Novel arrangement and comparative analysis of hsp90 family genes in three thermotolerant species of Stratiomyidae (Diptera).

    Science.gov (United States)

    Astakhova, L N; Zatsepina, O G; Przhiboro, A A; Evgen'ev, M B; Garbuz, D G

    2013-06-01

    The heat shock proteins belonging to the Hsp90 family (Hsp83 in Diptera) play a crucial role in the protection of cells due to their chaperoning functions. We sequenced hsp90 genes from three species of the family Stratiomyidae (Diptera) living in thermally different habitats and characterized by extraordinarily high thermotolerance. The sequence variation and structure of the hsp90 family genes were compared with previously described features of hsp70 copies isolated from the same species. Two functional hsp83 genes were found in the species studied, that are arranged in tandem orientation at least in one of them. This organization was not previously described. Stratiomyidae hsp83 genes share a high level of identity with hsp83 of Drosophila, and the deduced protein possesses five conserved amino acid sequence motifs characteristic of the Hsp90 family as well as the C-terminus MEEVD sequence characteristic of the cytosolic isoform. A comparison of the hsp83 promoters of two Stratiomyidae species from thermally contrasting habitats demonstrated that while both species contain canonical heat shock elements in the same position, only one of the species contains functional GAF-binding elements. Our data indicate that in the same species, hsp83 family genes show a higher evolution rate than the hsp70 family.

  2. Human calmodulin methyltransferase: expression, activity on calmodulin, and Hsp90 dependence.

    Directory of Open Access Journals (Sweden)

    Sophia Magen

    Full Text Available Deletion of the first exon of calmodulin-lysine N-methyltransferase (CaM KMT, previously C2orf34 has been reported in two multigene deletion syndromes, but additional studies on the gene have not been reported. Here we show that in the cells from 2p21 deletion patients the loss of CaM KMT expression results in accumulation of hypomethylated calmodulin compared to normal controls, suggesting that CaM KMT is essential for calmodulin methylation and there are no compensatory mechanisms for CaM methylation in humans. We have further studied the expression of this gene at the transcript and protein levels. We have identified 2 additional transcripts in cells of the 2p21 deletion syndrome patients that start from alternative exons positioned outside the deletion region. One of them starts in the 2(nd known exon, the other in a novel exon. The transcript starting from the novel exon was also identified in a variety of tissues from normal individuals. These new transcripts are not expected to produce proteins. Immunofluorescent localization of tagged CaM KMT in HeLa cells indicates that it is present in both the cytoplasm and nucleus of cells whereas the short isoform is localized to the Golgi apparatus. Using Western blot analysis we show that the CaM KMT protein is broadly expressed in mouse tissues. Finally we demonstrate that the CaM KMT interacts with the middle portion of the Hsp90 molecular chaperon and is probably a client protein since it is degraded upon treatment of cells with the Hsp90 inhibitor geldanamycin. These findings suggest that the CaM KMT is the major, possibly the single, methyltransferase of calmodulin in human cells with a wide tissue distribution and is a novel Hsp90 client protein. Thus our data provides basic information for a gene potentially contributing to the patient phenotype of two contiguous gene deletion syndromes.

  3. Proteomic analyses of the SMYD family interactomes identify HSP90 as a novel target for SMYD2

    Institute of Scientific and Technical Information of China (English)

    Mohamed Abu-Farha; Sylvain Lanouette; Fred Elisma; Véronique Tremblay; Jeffery Butson; Daniel Figeys; Jean-Francois Couture

    2011-01-01

    The SMYD (SET and MYND domain) family of lysine methyltransferases (KMTs) plays pivotal roles in various cellular processes,including gene expression regulation and DNA damage response.Initially identified as genuine histone methyltransferases,specific members of this family have recently been shown to methylate non-histone proteins such as p53,VEGFR,and the retinoblastoma tumor suppressor (pRb).To gain further functional insights into this family of KMTs,we generated the protein interaction network for three different human SMYD proteins (SMYD2,SMYD3,and SMYDS).Characterization of each SMYD protein network revealed that they associate with both shared and unique sets of proteins.Among those,we found that HsP90 and several of its co-chaperones interact specifically with the tetratrico peptide repeat (TPR)-containing SMYD2 and SMYD3.Moreover,using proteomic and biochemical techniques,we provide evidence that SMYD2 methylates K209 and K615 on HSP90 nucleotide-binding and dimerization domains,respectively.In addition,we found that each methylation site displays unique reactivity in regard to the presence of HsP90 co-chaperones,pH,and demethylation by the lysine amine oxidase LSD1,suggesting that alternative mechanisms control HsP90 methylation by SMYD2.Altogether,this study highlights the ability of SMYD proteins to form unique protein complexes that may underlie their various biological functions and the SMYD2-mediated methylation of the key molecular chaperone HSP90.%The SMYD (SET and MYND domain) family of lysine methyltransferases (KMTs) plays pivotal roles in various cellular processes, including gene expression regulation and DNA damage response. Initially identified as genuine histone methyltransferases, specific members of this family have recently been shown to methylate non-histone proteins such as p53, VEGFR, and the retinoblastoma tumor suppressor (pRb). To gain further functional insights into this family of KMTs, we generated the protein interaction

  4. The assembly and intermolecular properties of the Hsp70-Tomm34-Hsp90 molecular chaperone complex.

    Science.gov (United States)

    Trcka, Filip; Durech, Michal; Man, Petr; Hernychova, Lenka; Muller, Petr; Vojtesek, Borivoj

    2014-04-01

    Maintenance of protein homeostasis by molecular chaperones Hsp70 and Hsp90 requires their spatial and functional coordination. The cooperation of Hsp70 and Hsp90 is influenced by their interaction with the network of co-chaperone proteins, some of which contain tetratricopeptide repeat (TPR) domains. Critical to these interactions are TPR domains that target co-chaperone binding to the EEVD-COOH motif that terminates Hsp70/Hsp90. Recently, the two-TPR domain-containing protein, Tomm34, was reported to bind both Hsp70 and Hsp90. Here we characterize the structural basis of Tomm34-Hsp70/Hsp90 interactions. Using multiple methods, including pull-down assays, fluorescence polarization, hydrogen/deuterium exchange, and site-directed mutagenesis, we defined the binding activities and specificities of Tomm34 TPR domains toward Hsp70 and Hsp90. We found that Tomm34 TPR1 domain specifically binds Hsp70. This interaction is partly mediated by a non-canonical TPR1 two-carboxylate clamp and is strengthened by so far unidentified additional intermolecular contacts. The two-carboxylate clamp of the isolated TPR2 domain has affinity for both chaperones, but as part of the full-length Tomm34 protein, the TPR2 domain binds specifically Hsp90. These binding properties of Tomm34 TPR domains thus enable simultaneous binding of Hsp70 and Hsp90. Importantly, we provide evidence for the existence of an Hsp70-Tomm34-Hsp90 tripartite complex. In addition, we defined the basic conformational demands of the Tomm34-Hsp90 interaction. These results suggest that Tomm34 represents a novel scaffolding co-chaperone of Hsp70 and Hsp90, which may facilitate Hsp70/Hsp90 cooperation during protein folding.

  5. A novel biomarker for marine environmental pollution of HSP90 from Mytilus coruscus.

    Science.gov (United States)

    Liu, Huihui; Wu, Jiong; Xu, Mengshan; He, Jianyu

    2016-10-15

    Heat shock protein 90 (HSP90) is a conserved molecular chaperone contributing to cell cycle control, organism development and the proper regulation of cytosolic proteins. The full-length HSP90 cDNA of Mytilus coruscus (McHSP90, KT946644) was 2420bp, including an ORF of 2169bp encoding a polypeptide of 722 amino acids with predicted pI/MW 4.89/83.22kDa. BLASTp analysis and phylogenetic relationship strongly suggested McHSP90 was a member of HSP90 family, and it was highly conserved with other known HSP90, especially in the HSP90 family signatures, ATP/GTP-Binding sites and 'EEVD' motif. The mRNA of McHSP90 in haemolymph was upregulated in all treatments including Vibrio alginolyticus and Vibrio harveyi challenge, metals stresses (copper and cadmium) and 180 CST fuel exposure. All the results implied the expression of McHSP90 could be affected by Vibrio challenge and environmental stress, which might help us gain more insight into the molecular mechanism of HSP against adverse stresses in mollusca.

  6. 真蛸热休克蛋白90基因(HSP90)的克隆及表达%Molecular cloning and feature analysis of heat shock protein 90 ( HSP90 ) from Octopus vulgaris

    Institute of Scientific and Technical Information of China (English)

    孙田田; 苏永全; 洪婧妮; 邬阳; 张曼; 毛勇

    2012-01-01

    为深入了解真蛸热应激响应机制,实验以真蛸的应激蛋白为研究对象,借助同源扩增和cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)技术获得真蛸热休克蛋白90( HSP90)的cDNA全序列(2 709 bp),它包含119 bp的5′非编码区(untranslated regions,UTR)、454 bp的3′UTR和2 136 bp的开放阅读框(opening reading frame,ORF),ORF共编码71 1个氨基酸,推算其分子量为81.5 ku,理论等电点为5.09.同源分析显示,所推导的氨基酸序列高度保守,并且含有HSP90家族特有的5个保守信号序列区域.实时荧光定量PCR分析表明,该基因在所有选取的组织中均有表达,肝组织中表达量最高.%Octopus vulgaris,which owns a number of unique stress protection mechanisms is considered to be the most intelligent species of all invertebrates. A 2 709 bp full-length cDNA sequence of heat shock protein 90 ( HSP90 ) gene from O. vulgaris was obtained by homologous amplification and rapid amplification of cDNA ends (RACE). It consisted of a 119 bp 5'untranslated region (UTR) ,a2 136 bp open reading frame(ORF)and a 454 bp 3'UTR. The inferred amino acids sequence was composed of 711 amino acids, whose molecular weight and isoelectric point were 81. 5 ku and 5. 09, respectively. Homologous analysis showed the inferred amino acids sequence was highly conserved and contained five classical HSP90 signature sequences. Real-time quantitative PCR ( RT-PCR) results displayed HSP90 expressed in every tissues chosen, with the most in liver. This study which was the first time to obtain HSP90 gene from Cephalopod played an important role in studying stress mechanisms on the most intelligent invertebrate.

  7. BIIB021, a novel Hsp90 inhibitor, sensitizes esophageal squamous cell carcinoma to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Tong; Bao, Ci-Hang; Jia, Yi-Bin; Wang, Nana [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Ma, Wei [Department of Radiation Oncology, Cancer Hospital, General Hospital of Ningxia Medical University, Yinchuan 750000 (China); Liu, Fang [Medical Imaging, Shandong Medical College, Jinan 250002 (China); Wang, Cong; Wang, Jian-Bo; Song, Qing-Xu [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Cheng, Yu-Feng, E-mail: qlcyf1965@126.com [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China)

    2014-10-03

    Highlights: • BIIB021 downregulated radioresistant proteins in ESCC cell lines. • BIIB021 increased radiation-induced apoptotic cells. • BIIB021 enhanced G{sub 2} arrest in ESCC cell lines. • BIIB021 is a good candidate for radiosensitizer in radiotherapy of ESCC patients. - Abstract: BIIB021 is a novel, orally available inhibitor of heat shock protein 90 (Hsp90) that is currently in phase I/II clinical trials. BIIB021 induces the apoptosis of various types of tumor cells in vitro and in vivo. The aim of this study is to investigate the effect of BIIB021 on the radiosensitivity of esophageal squamous cell carcinoma (ESCC). The results indicated that BIIB021 exhibited strong antitumor activity in ESCC cell lines, either as a single agent or in combination with radiation. BIIB021 significantly downregulated radioresistant proteins including EGFR, Akt, Raf-1 of ESCC cell lines, increased apoptotic cells and enhanced G{sub 2} arrest that is more radiosensitive cell cycle phase. These results suggest that this synthetic Hsp90 inhibitor simultaneously affects multiple pathways involved in tumor development and progression in the ESCC setting and may represent a better strategy for the treatment of ESCC patients, either as a monotherapy or a radiosensitizer.

  8. Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin inhibits the proliferation of ARPE-19 cells

    Directory of Open Access Journals (Sweden)

    Wang Lin

    2010-04-01

    Full Text Available Abstract Background The antiproliferative effect of the Hsp90 inhibitor 17-AAG (17-allylamino-17-demethoxygeldanamycin on human retinal pigment epithelial cells is investigated. Methods MTT and flow cytometry were used to study the antiproliferative effects of the 17-AAG treatment of ARPE-19 cells. 2D gel electrophoresis (2-DE and mass spectrometry were applied to detect the altered expression of proteins, which was verified by real-time PCR. Gene Ontology analysis and Ingenuity Pathway Analysis (IPA were utilized to analyze the signaling pathways, cellular location, function, and network connections of the identified proteins. And SOD assay was employed to confirm the analysis. Results 17-AAG suppressed the proliferation of ARPE-19 cells by inducing cell cycle arrest and apoptosis. Proteomic analysis revealed that the expression of 94 proteins was altered by a factor of more than 1.5 following exposure to 17-AAG. Of these 94, 87 proteins were identified. Real-time PCR results indicated that Hsp90 and Hsp70, which were not identified by proteomic analysis, were both upregulated upon 17-AAG treatment. IPA revealed that most of the proteins have functions that are related to oxidative stress, as verified by SOD assay, while canonical pathway analysis revealed glycolysis/gluconeogenesis. Conclusions 17-AAG suppressed the proliferation of ARPE-19 cells by inducing cell cycle arrest and apoptosis, and possibly by oxidative stress.

  9. Cytotoxic activity to acute myeloid leukemia cells by Antp-TPR hybrid peptide targeting Hsp90.

    Science.gov (United States)

    Horibe, Tomohisa; Kawamoto, Megumi; Kohno, Masayuki; Kawakami, Koji

    2012-07-01

    We previously reported that Antp-TPR hybrid peptide inhibited the interaction of Hsp90 with TPR2A and had selective cytotoxic activity discriminating between normal and cancer cells to induce cancer cell death. In this study, we investigated the cytotoxic activity of Antp-TPR peptide toward acute myeloid leukemia (AML) cells. It was demonstrated that Antp-TPR peptide induced AML cell death in cell lines such as U937, K562, THP-1, and HL-60 via activation of caspases 3 and 7, and disruption of mitochondrial membrane potential. Conversely, Antp-TPR peptide did not reduce the viability of normal cells including peripheral blood mononuclear cells (PBMCs), although both geldanamycin and 17-AAG, small-molecule inhibitors of Hsp90, mediated cytotoxicity to these normal cells at low concentrations. In addition, mutation analysis of TPR peptide demonstrated that the highly conserved amino acids Lys and Arg were critical to the cytotoxic activity. These results indicated that Antp-TPR hybrid peptide would provide potent and selective therapeutic options in the treatment of AML.

  10. Leptin increases HER2 protein levels through a STAT3-mediated up-regulation of Hsp90 in breast cancer cells.

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    Giordano, Cinzia; Vizza, Donatella; Panza, Salvatore; Barone, Ines; Bonofiglio, Daniela; Lanzino, Marilena; Sisci, Diego; De Amicis, Francesca; Fuqua, Suzanne A W; Catalano, Stefania; Andò, Sebastiano

    2013-06-01

    Obesity condition confers risks to breast cancer development and progression, and several reports indicate that the adipokine leptin, whose synthesis and plasma levels increase with obesity, might play an important role in modulating breast cancer cell phenotype. Functional crosstalk occurring between leptin and different signaling molecules contribute to breast carcinogenesis. In this study, we show, in different human breast cancer cell lines, that leptin enhanced the expression of a chaperone protein Hsp90 resulting in increased HER2 protein levels. Silencing of Hsp90 gene expression by RNA interference abrogated leptin-mediated HER2 up-regulation. Leptin effects were dependent on JAK2/STAT3 activation, since inhibition of this signaling cascade by AG490 or ectopic expression of a STAT3 dominant negative abrogated leptin-induced HER2 and Hsp90 expressions. Functional experiments showed that leptin treatment significantly up-regulated human Hsp90 promoter activity. This occurred through an enhanced STAT3 transcription factor binding to its specific responsive element located in the Hsp90 promoter region as revealed by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Analysis of HER2, Akt and MAPK phosphorylation levels revealed that leptin treatment amplified the responsiveness of breast cancer cells to growth factor stimulation. Furthermore, we found that long-term leptin exposure reduced sensitivity of breast cancer cells to the antiestrogen tamoxifen. In the same experimental conditions, the combined treatment of tamoxifen with the Hsp90 inhibitor 17-AAG completely abrogated leptin-induced anchorage-independent breast cancer cell growth. In conclusion, our results highlight, for the first time, the ability of the adipocyte-secreted factor leptin to modulate Hsp90/HER2 expressions in breast cancer cells providing novel insights into the molecular mechanism linking obesity to breast cancer growth and progression.

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

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    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.

  12. Hsp90 orchestrates transcriptional regulation by Hsf1 and cell wall remodelling by MAPK signalling during thermal adaptation in a pathogenic yeast.

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    Michelle D Leach

    2012-12-01

    Full Text Available Thermal adaptation is essential in all organisms. In yeasts, the heat shock response is commanded by the heat shock transcription factor Hsf1. Here we have integrated unbiased genetic screens with directed molecular dissection to demonstrate that multiple signalling cascades contribute to thermal adaptation in the pathogenic yeast Candida albicans. We show that the molecular chaperone heat shock protein 90 (Hsp90 interacts with and down-regulates Hsf1 thereby modulating short term thermal adaptation. In the longer term, thermal adaptation depends on key MAP kinase signalling pathways that are associated with cell wall remodelling: the Hog1, Mkc1 and Cek1 pathways. We demonstrate that these pathways are differentially activated and display cross talk during heat shock. As a result ambient temperature significantly affects the resistance of C. albicans cells to cell wall stresses (Calcofluor White and Congo Red, but not osmotic stress (NaCl. We also show that the inactivation of MAP kinase signalling disrupts this cross talk between thermal and cell wall adaptation. Critically, Hsp90 coordinates this cross talk. Genetic and pharmacological inhibition of Hsp90 disrupts the Hsf1-Hsp90 regulatory circuit thereby disturbing HSP gene regulation and reducing the resistance of C. albicans to proteotoxic stresses. Hsp90 depletion also affects cell wall biogenesis by impairing the activation of its client proteins Mkc1 and Hog1, as well as Cek1, which we implicate as a new Hsp90 client in this study. Therefore Hsp90 modulates the short term Hsf1-mediated activation of the classic heat shock response, coordinating this response with long term thermal adaptation via Mkc1- Hog1- and Cek1-mediated cell wall remodelling.

  13. Spermatogenesis arrest caused by conditional deletion of Hsp90α in adult mice

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    Chiaki Kajiwara

    2012-08-01

    It is controversial whether a functional androgen receptor (AR on germ cells, including spermatogonia, is essential for their development into sperm and, thus, initiation and maintenance of spermatogenesis. It was recently shown that many spermatocytes underwent apoptosis in the testes of Hsp90α KO mice. We had generated Hsp90α KO mice independently and confirmed this phenotype. However, the important question of whether Hsp90α is required to maintain spermatogenesis in adult mice in which testicular maturation is already completed could not be addressed using these conventional KO mice. To answer this question, we generated a tamoxifen-inducible deletion mutant of Hsp90α and found that conditional deletion of Hsp90α in adult mice caused even more severe apoptosis in germ cells beyond the pachytene stage, leading to complete arrest of spermatogenesis and testicular atrophy. Importantly, immunohistochemical analysis revealed that AR expression in WT testis was more evident in spermatogonia than in spermatocytes, whereas its expression was aberrant and ectopic in Hsp90α KO testis, raising the possibility that an AR abnormality in primordial germ cells is involved in spermatogenesis arrest in the Hsp90α KO mice. Our results suggest that the AR, specifically chaperoned by Hsp90α in spermatogonia, is critical for maintenance of established spermatogenesis and for survival of spermatocytes in adult testis, in addition to setting the first wave of spermatogenesis before puberty.

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

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

    2016-01-01

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

  15. Analysis of Hsp90 cochaperone interactions reveals a novel mechanism for TPR protein recognition.

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    Chadli, Ahmed; Bruinsma, Elizabeth S; Stensgard, Bridget; Toft, David

    2008-03-01

    The chaperone Hsp90 is required for the appropriate regulation of numerous key signaling molecules, including the progesterone receptor (PR). Many important cochaperones bind Hsp90 through their tetratricopeptide repeat (TPR) domains. Two such proteins, GCUNC45 and FKBP52, assist PR chaperoning and are thought to interact sequentially with PR-Hsp90 complexes. TPR proteins bind to the C-terminal MEEVD sequence of Hsp90, but GCUNC45 has been shown also to bind to a novel site near the N-terminus. We now show that FKBP52 is also able to bind to this site, and that these two cochaperones act competitively, through Hsp90, to modulate PR activity. The N-terminal site involves noncontiguous amino acids within or near the ATP binding pocket of Hsp90. TPR interactions at this site are thus strongly regulated by nucleotide binding and Hsp90 conformation. We propose an expanded model for client chaperoning in which the coordinated use of TPR recognition sites at both N- and C-terminal ends of Hsp90 enhances its ability to coordinate interactions with multiple TPR partners.

  16. Why is this effective HSP90 inhibitor not being developed in HER2+ breast cancer?

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    Arteaga, Carlos L

    2011-08-01

    Inhibition of the HSP90 chaperone leads to degradation of the HER2 receptor. The HSP90 inhibitor tanespimycin in combination with trastuzumab is active in patients with HER2-overexpressing metastatic breast cancer. This combination is one of several HER2-targeted therapies that will significantly improve the outcome of patients with this subtype of breast cancer.

  17. Induction of premature senescence by hsp90 inhibition in small cell lung cancer.

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    Ian J Restall

    Full Text Available BACKGROUND: The molecular chaperone Hsp90 is a promising new target in cancer therapy and selective Hsp90 inhibitors are currently in clinical trials. Previously these inhibitors have been reported to induce either cell cycle arrest or cell death in cancer cells. Whether the cell cycle arrest is reversible or irreversible has not generally been assessed. Here we have examined in detail the cell cycle arrest and cell death responses of human small cell lung cancer cell lines to Hsp90 inhibition. METHODOLOGY/PRINCIPAL FINDINGS: In MTT assays, small cell lung cancer cells showed a biphasic response to the Hsp90 inhibitors geldanamycin and radicicol, with low concentrations causing proliferation arrest and high concentrations causing cell death. Assessment of Hsp90 intracellular activity using loss of client protein expression showed that geldanamycin concentrations that inhibited Hsp90 correlated closely with those causing proliferation arrest but not cell death. The proliferation arrest induced by low concentrations of geldanamycin was not reversed for a period of over thirty days following drug removal and showed features of senescence. Rare populations of variant small cell lung cancer cells could be isolated that had additional genetic alterations and no longer underwent irreversible proliferation arrest in response to Hsp90 inhibitors. CONCLUSIONS/SIGNIFICANCE: We conclude that: (1 Hsp90 inhibition primarily induces premature senescence, rather than cell death, in small cell lung cancer cells; (2 small cell lung cancer cells can bypass this senescence through further genetic alterations; (3 Hsp90 inhibitor-induced cell death in small cell lung cancer cells is due to inhibition of a target other than cytosolic Hsp90. These results have implications with regard to how these inhibitors will behave in clinical trials and for the design of future inhibitors in this class.

  18. Hsp90 is a direct target of the anti-allergic drugs disodium cromoglycate and amlexanox.

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    Okada, Miki; Itoh, Hideaki; Hatakeyama, Takashi; Tokumitsu, Hiroshi; Kobayashi, Ryoji

    2003-09-01

    Hsp90 (heat-shock protein 90) alone can act to prevent protein aggregation and promote refolding in vitro, but in vivo it operates as a part of a multichaperone complex, which includes Hsp70 and cohort proteins. Since the physiological function of Hsp90 is not yet fully understood, the development of specific antagonists might open new lines of investigation on the role of Hsp90. In an effort to discover Hsp90 antagonists, we screened many drugs and found that the anti-allergic drugs DSCG (disodium cromoglycate) and amlexanox target Hsp90. Both drugs were found to bind directly wild-type Hsp90 via the N- and C-terminal domains. Both drugs strongly suppressed the in vitro chaperone activity of native Hsp90 towards citrate synthase at 1.5-3.0 microM. Amlexanox suppressed C-terminal chaperone activity in vitro, but not N-terminal chaperone activity, and inhibited the association of cohort proteins, such as cyclophilin 40 and Hsp-organizing protein, to the C-terminal domain of Hsp90. These data suggest that amlexanox might disrupt the multichaperone complex, including Hsp70 and cohort proteins, both in vitro and in vivo. Although DSCG inhibited the in vitro chaperone activity of the N-terminal domain, the drug had no effect either on the C-terminal chaperone activity or on the association of the cohort proteins with the C-terminus of Hsp90. The physiological significance of these interactions in vivo remains to be investigated further, but undoubtedly must be taken into account when considering the pharmacology of anti-allergic drugs. DSCG and amlexanox may serve as useful tools for evaluating the physiological significance of Hsp90.

  19. Epigallocatechin-3-gallate suppresses the expression of HSP70 and HSP90 and exhibits anti-tumor activity in vitro and in vivo

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    Yoon Jung-Hoon

    2010-06-01

    Full Text Available Abstract Background Epigallocatechin-3-gallate (EGCG, one of the major catechins in green tea, is a potential chemopreventive agent for various cancers. The aim of this study was to examine the effect of EGCG on the expression of heat shock proteins (HSPs and tumor suppression. Methods Cell colony formation was evaluated by a soft agar assay. Transcriptional activity of HSP70 and HSP90 was determined by luciferase reporter assay. An EGCG-HSPs complex was prepared using EGCG attached to the cyanogen bromide (CNBr-activated Sepharose 4B. In vivo effect of EGCG on tumor growth was examined in a xenograft model. Results Treatment with EGCG decreased cell proliferation and colony formation of MCF-7 human breast cancer cells. EGCG specifically inhibited the expression of HSP70 and HSP90 by inhibiting the promoter activity of HSP70 and HSP90. Pretreatment with EGCG increased the stress sensitivity of MCF-7 cells upon heat shock (44°C for 1 h or oxidative stress (H2O2, 500 μM for 24 h. Moreover, treatment with EGCG (10 mg/kg in a xenograft model resulted in delayed tumor incidence and reduced tumor size, as well as the inhibition of HSP70 and HSP90 expression. Conclusions Overall, these findings demonstrate that HSP70 and HSP90 are potent molecular targets of EGCG and suggest EGCG as a drug candidate for the treatment of human cancer.

  20. Inhibition of HSP90 Promotes Neural Stem Cell Survival from Oxidative Stress through Attenuating NF-κB/p65 Activation

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    Qian Liu

    2016-01-01

    Full Text Available Stem cell survival after transplantation determines the efficiency of stem cell treatment, which develops as a novel potential therapy for several central nervous system (CNS diseases in recent decades. The engrafted stem cells face the damage of oxidative stress, inflammation, and immune response at the lesion point in host. Among the damaging pathologies, oxidative stress directs stem cells to apoptosis and even death through several signalling pathways and DNA damage. However, the in-detail mechanism of stem cell survival from oxidative stress has not been revealed clearly. Here, in this study, we used hydrogen peroxide (H2O2 to induce the oxidative damage on neural stem cells (NSCs. The damage was in consequence demonstrated involving the activation of heat shock protein 90 (HSP90 and NF-κB/p65 signalling pathways. Further application of the pharmacological inhibitors, respectively, targeting at each signalling indicated an upper-stream role of HSP90 upon NF-κB/p65 on NSCs survival. Preinhibition of HSP90 with the specific inhibitor displayed a significant protection on NSCs against oxidative stress. In conclusion, inhibition of HSP90 would attenuate NF-κB/p65 activation by oxidative induction and promote NSCs survival from oxidative damage. The HSP90/NF-κB mechanism provides a new evidence on rescuing NSCs from oxidative stress and also promotes the stem cell application on CNS pathologies.

  1. Inhibition of HSP90 Promotes Neural Stem Cell Survival from Oxidative Stress through Attenuating NF-κB/p65 Activation

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    Jiang, Wenkai; Zhou, Lin

    2016-01-01

    Stem cell survival after transplantation determines the efficiency of stem cell treatment, which develops as a novel potential therapy for several central nervous system (CNS) diseases in recent decades. The engrafted stem cells face the damage of oxidative stress, inflammation, and immune response at the lesion point in host. Among the damaging pathologies, oxidative stress directs stem cells to apoptosis and even death through several signalling pathways and DNA damage. However, the in-detail mechanism of stem cell survival from oxidative stress has not been revealed clearly. Here, in this study, we used hydrogen peroxide (H2O2) to induce the oxidative damage on neural stem cells (NSCs). The damage was in consequence demonstrated involving the activation of heat shock protein 90 (HSP90) and NF-κB/p65 signalling pathways. Further application of the pharmacological inhibitors, respectively, targeting at each signalling indicated an upper-stream role of HSP90 upon NF-κB/p65 on NSCs survival. Preinhibition of HSP90 with the specific inhibitor displayed a significant protection on NSCs against oxidative stress. In conclusion, inhibition of HSP90 would attenuate NF-κB/p65 activation by oxidative induction and promote NSCs survival from oxidative damage. The HSP90/NF-κB mechanism provides a new evidence on rescuing NSCs from oxidative stress and also promotes the stem cell application on CNS pathologies.

  2. A primate specific extra domain in the molecular chaperone Hsp90.

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    Vishwadeepak Tripathi

    Full Text Available Hsp90 (heat shock protein 90 is an essential molecular chaperone that mediates folding and quality control of client proteins. Many of them such as protein kinases, steroid receptors and transcription factors are involved in cellular signaling processes. Hsp90 undergoes an ATP hydrolysis dependent conformational cycle to assist folding of the client protein. The canonical Hsp90 shows a typical composition of three distinct domains and interacts with individual cochaperone partners such as Hop, Cdc37 and Aha1 (activator of Hsp90 ATPase that regulate the reaction cycle of the molecular chaperone. A bioinformatic survey identified an additional domain of 122 amino acids in front of the canonical Hsp90 sequence. This extra domain (E domain is specific to the Catarrhini or drooping nose monkeys, a subdivision of the higher primates that includes man, the great apes and the old world monkeys but is absent from all other species. Our biochemical analysis reveals that Hsp103 associates with cochaperone proteins such as Hop, Cdc37 and Aha1 similar to Hsp90. However, the extra domain reduces the ATP hydrolysis rate to about half when compared to Hsp90 thereby acting as a negative regulator of the molecular chaperonés intrinsic ATPase activity.

  3. Phylogenetic analysis of eukaryotes using heat-shock protein Hsp90.

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    Stechmann, Alexandra; Cavalier-Smith, Thomas

    2003-10-01

    Most eukaryote molecular phylogenies have been based on small-subunit ribosomal RNA as its database includes the most species, but serious problems have been encountered that can make these trees misleading. More recent studies using concatenated protein sequences have increased the data per organism, reducing misleading signals from a single sequence, but taxon sampling is limited. To increase the database of protein-coding genes we sequenced the cytosolic form of heat-shock protein Hsp90 from a broad variety of previously unsampled eukaryote groups: protozoan flagellates (phyla Choanozoa, Apusozoa, Cercozoa) and all three groups of chromists (Cryptophyta, Heterokonta, Haptophyta). Gamma-corrected distance trees robustly show three groups: bacterial sequences are sister to all eukaryote sequences, which are cleanly subdivided into the cytosolic sequences and a clade comprising the chloroplast and endoplasmic reticulum (ER) Hsp90 sequences. The eukaryote cytosolic sequences comprise a robust opisthokont clade (animals/Choanozoa/fungi), a bikont clade, and an amoebozoan branch. However their topology is not robust. When the cytosolic sequences are rooted using only the ER/ chloroplast clade as outgroup the amoebozoan Dictyostelium is sister to the opisthokonts forming a unikont clade in the distance tree. Congruence of this tree with that for concatenated mitochondrial proteins suggests that the root of the eukaryote tree is between unikonts and bikonts. Gamma-corrected maximum likelihood analyses of cytosolic sequences alone (519 unambiguously aligned amino acid positions) show bikonts as a clade, as do least-squares distance trees, but with other distance methods and parsimony the sole amoebozoan species branches weakly within bikonts. Choanozoa are clearly sisters to animals. Some major bikont groups (e.g. green plants, alveolates, Euglenozoa) are consistently recovered, but others (e.g. discicristates, chromalveolates) appear only in some trees; the backbone of

  4. Hsp90 is important for fecundity, longevity, and buffering of cryptic deleterious variation in wild fly populations

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    Chen Bing

    2012-02-01

    Full Text Available Abstract Background In the laboratory, the Drosophila melanogaster heat shock protein Hsp90 can buffer the phenotypic effects of genetic variation. Laboratory experiments either manipulate Hsp90 activity pharmacologically, or they induce mutations with strong effects in the gene Hsp83, the single-copy fly gene encoding Hsp90. It is unknown whether observations from such laboratory experiments are relevant in the wild. Results We here study naturally occurring mutations in Hsp83, and their effects on fitness and phenotypic buffering in flies derived from wild populations. We examined more than 4500 flies from 42 Drosophila populations distributed world-wide for insertions or deletions of mobile DNA in or near the Hsp83 gene. The insertions we observed occur at low population frequencies, and reduce Hsp83 gene expression. In competition experiments, mutant flies performed much more poorly than wild-type flies. Mutant flies were also significantly less fecund and shorter-lived than wild-type flies, as well as less well buffered against cryptic deleterious variation, as we show through inbreeding experiments. Specifically, in Hsp83 mutant flies female fecundity dropped to much lower levels after inbreeding than in wild-type flies. At even slightly elevated temperatures, inbred mutant Hsp83 populations went extinct, whereas inbred wild-type populations persisted. Conclusions Our work shows that Hsp90, a regulator of the stress response and of signaling, helps buffer deleterious variation in fruit flies derived from wild population, and that its buffering role becomes even more important under heat stress.

  5. Probing molecular mechanisms of the Hsp90 chaperone: biophysical modeling identifies key regulators of functional dynamics.

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    Anshuman Dixit

    Full Text Available Deciphering functional mechanisms of the Hsp90 chaperone machinery is an important objective in cancer biology aiming to facilitate discovery of targeted anti-cancer therapies. Despite significant advances in understanding structure and function of molecular chaperones, organizing molecular principles that control the relationship between conformational diversity and functional mechanisms of the Hsp90 activity lack a sufficient quantitative characterization. We combined molecular dynamics simulations, principal component analysis, the energy landscape model and structure-functional analysis of Hsp90 regulatory interactions to systematically investigate functional dynamics of the molecular chaperone. This approach has identified a network of conserved regions common to the Hsp90 chaperones that could play a universal role in coordinating functional dynamics, principal collective motions and allosteric signaling of Hsp90. We have found that these functional motifs may be utilized by the molecular chaperone machinery to act collectively as central regulators of Hsp90 dynamics and activity, including the inter-domain communications, control of ATP hydrolysis, and protein client binding. These findings have provided support to a long-standing assertion that allosteric regulation and catalysis may have emerged via common evolutionary routes. The interaction networks regulating functional motions of Hsp90 may be determined by the inherent structural architecture of the molecular chaperone. At the same time, the thermodynamics-based "conformational selection" of functional states is likely to be activated based on the nature of the binding partner. This mechanistic model of Hsp90 dynamics and function is consistent with the notion that allosteric networks orchestrating cooperative protein motions can be formed by evolutionary conserved and sparsely connected residue clusters. Hence, allosteric signaling through a small network of distantly connected

  6. HSP90 Inhibitors, Geldanamycin and Radicicol, Enhance Fisetin-Induced Cytotoxicity via Induction of Apoptosis in Human Colonic Cancer Cells

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    Ming-Shun Wu

    2013-01-01

    Full Text Available We revealed the cytotoxic effect of the flavonoid, fisetin (FIS, on human COLO205 colon cancer cells in the presence and absence of the HSP90 inhibitors, geldanamycin (GA and radicicol (RAD. Compared to FIS treatment alone of COLO205 cells, GA and RAD significantly enhanced FIS-induced cytotoxicity, increased expression of cleaved caspase-3 and the PAPR protein, and produced a greater density of DNA ladder formation. GA and RAD also reduced the MMPs with induction of caspase-9 protein cleavage in FIS-treated COLO205 cells. Increased caspase-3 and -9 activities were detected in COLO205 cells treated with FIS+GA or FIS+RAD, and the intensity of DNA ladder formation induced by FIS+GA was reduced by adding the caspase-3 inhibitor, DEVD-FMK. A decrease in Bcl-2 but not Bcl-XL or Bax protein by FIS+GA or FIS+RAD was identified in COLO205 cells by Western blotting. A reduction in p53 protein with increased ubiquitin-tagged proteins was observed in COLO205 cells treated with FIS+GA or FIS+RAD. Furthermore, GA and RAD reduced the stability of the p53 protein in COLO205 cells under FIS stimulation. The evidence supports HSP90 inhibitors possibly sensitizing human colon cancer cells to FIS-induced apoptosis, and treating colon cancer by combining HSP90 inhibitors with FIS deserves further in vivo study.

  7. Multifaceted intervention by the Hsp90 inhibitor ganetespib (STA-9090 in cancer cells with activated JAK/STAT signaling.

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    David A Proia

    Full Text Available There is accumulating evidence that dysregulated JAK signaling occurs in a wide variety of cancer types. In particular, mutations in JAK2 can result in the constitutive activation of STAT transcription factors and lead to oncogenic growth. JAK kinases are established Hsp90 client proteins and here we show that the novel small molecule Hsp90 inhibitor ganetespib (formerly STA-9090 exhibits potent in vitro and in vivo activity in a range of solid and hematological tumor cells that are dependent on JAK2 activity for growth and survival. Of note, ganetespib treatment results in sustained depletion of JAK2, including the constitutively active JAK2(V617F mutant, with subsequent loss of STAT activity and reduced STAT-target gene expression. In contrast, treatment with the pan-JAK inhibitor P6 results in only transient effects on these processes. Further differentiating these modes of intervention, RNA and protein expression studies show that ganetespib additionally modulates cell cycle regulatory proteins, while P6 does not. The concomitant impact of ganetespib on both cell growth and cell division signaling translates to potent antitumor efficacy in mouse models of xenografts and disseminated JAK/STAT-driven leukemia. Overall, our findings support Hsp90 inhibition as a novel therapeutic approach for combating diseases dependent on JAK/STAT signaling, with the multimodal action of ganetespib demonstrating advantages over JAK-specific inhibitors.

  8. Synthesis and evaluation of novologues as C-terminal Hsp90 inhibitors with cytoprotective activity against sensory neuron glucotoxicity.

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    Kusuma, Bhaskar Reddy; Zhang, Liang; Sundstrom, Teather; Peterson, Laura B; Dobrowsky, Rick T; Blagg, Brian S J

    2012-06-28

    Compound 2 (KU-32) is a first-generation novologue (a novobiocin-based, C-terminal, heat shock protein 90 (Hsp90) inhibitor) that decreases glucose-induced death of primary sensory neurons and reverses numerous clinical indices of diabetic peripheral neuropathy in mice. The current study sought to exploit the C-terminal binding site of Hsp90 to determine whether the optimization of hydrogen bonding and hydrophobic interactions of second-generation novologues could enhance neuroprotective activity. Using a series of substituted phenylboronic acids to replace the coumarin lactone of 2, we identified that electronegative atoms placed at the meta-position of the B-ring exhibit improved cytoprotective activity, which is believed to result from favorable interactions with Lys539 in the Hsp90 C-terminal binding pocket. Consistent with these results, a meta-3-fluorophenyl substituted novologue (13b) exhibited a 14-fold lower ED(50) for protection against glucose-induced toxicity of primary sensory neurons compared to 2.

  9. Loss of Smyhc1 or Hsp90alpha1 function results in different effects on myofibril organization in skeletal muscles of zebrafish embryos.

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    Marta Codina

    Full Text Available BACKGROUND: Myofibrillogenesis requires the correct folding and assembly of sarcomeric proteins into highly organized sarcomeres. Heat shock protein 90alpha1 (Hsp90alpha1 has been implicated as a myosin chaperone that plays a key role in myofibrillogenesis. Knockdown or mutation of hsp90alpha1 resulted in complete disorganization of thick and thin filaments and M- and Z-line structures. It is not clear whether the disorganization of these sarcomeric structures is due to a direct effect from loss of Hsp90alpha1 function or indirectly through the disorganization of myosin thick filaments. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we carried out a loss-of-function analysis of myosin thick filaments via gene-specific knockdown or using a myosin ATPase inhibitor BTS (N-benzyl-p-toluene sulphonamide in zebrafish embryos. We demonstrated that knockdown of myosin heavy chain 1 (myhc1 resulted in sarcomeric defects in the thick and thin filaments and defective alignment of Z-lines. Similarly, treating zebrafish embryos with BTS disrupted thick and thin filament organization, with little effect on the M- and Z-lines. In contrast, loss of Hsp90alpha1 function completely disrupted all sarcomeric structures including both thick and thin filaments as well as the M- and Z-lines. CONCLUSION/SIGNIFICANCE: Together, these studies indicate that the hsp90alpha1 mutant phenotype is not simply due to disruption of myosin folding and assembly, suggesting that Hsp90alpha1 may play a role in the assembly and organization of other sarcomeric structures.

  10. Genome-wide dissection of AP2/ERF and HSP90 gene families in five legumes and expression profiles in chickpea and pigeonpea.

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    Agarwal, Gaurav; Garg, Vanika; Kudapa, Himabindu; Doddamani, Dadakhalandar; Pazhamala, Lekha T; Khan, Aamir W; Thudi, Mahendar; Lee, Suk-Ha; Varshney, Rajeev K

    2016-07-01

    APETALA2/ethylene response factor (AP2/ERF) and heat-shock protein 90 (HSP90) are two significant classes of transcription factor and molecular chaperone proteins which are known to be implicated under abiotic and biotic stresses. Comprehensive survey identified a total of 147 AP2/ERF genes in chickpea, 176 in pigeonpea, 131 in Medicago, 179 in common bean and 140 in Lotus, whereas the number of HSP90 genes ranged from 5 to 7 in five legumes. Sequence alignment and phylogenetic analyses distinguished AP2, ERF, DREB, RAV and soloist proteins, while HSP90 proteins segregated on the basis of their cellular localization. Deeper insights into the gene structure allowed ERF proteins to be classified into AP2s based on DNA-binding domains, intron arrangements and phylogenetic grouping. RNA-seq and quantitative real-time PCR (qRT-PCR) analyses in heat-stressed chickpea as well as Fusarium wilt (FW)- and sterility mosaic disease (SMD)-stressed pigeonpea provided insights into the modus operandi of AP2/ERF and HSP90 genes. This study identified potential candidate genes in response to heat stress in chickpea while for FW and SMD stresses in pigeonpea. For instance, two DREB genes (Ca_02170 and Ca_16631) and three HSP90 genes (Ca_23016, Ca_09743 and Ca_25602) in chickpea can be targeted as potential candidate genes. Similarly, in pigeonpea, a HSP90 gene, C.cajan_27949, was highly responsive to SMD in the resistant genotype ICPL 20096, can be recommended for further functional validation. Also, two DREB genes, C.cajan_41905 and C.cajan_41951, were identified as leads for further investigation in response to FW stress in pigeonpea.

  11. A review of recent patents on the protozoan parasite HSP90 as a drug target.

    Science.gov (United States)

    Angel, Sergio O; Matrajt, Mariana; Echeverria, Pablo C

    2013-04-01

    Diseases caused by protozoan parasites are still an important health problem. These parasites can cause a wide spectrum of diseases, some of which are severe and have high morbidity or mortality if untreated. Since they are still uncontrolled, it is important to find novel drug targets and develop new therapies to decrease their remarkable social and economic impact on human societies. In the past years, human HSP90 has become an interesting drug target that has led to a large number of investigations both at state organizations and pharmaceutical companies, followed by clinical trials. The finding that HSP90 has important biological roles in some protozoan parasites like Plasmodium spp, Toxoplasma gondii and trypanosomatids has allowed the expansion of the results obtained in human cancer to these infections. This review summarizes the latest important findings showing protozoan HSP90 as a drug target and presents three patents targeting T. gondii, P. falciparum and trypanosomatids HSP90.

  12. Heat Shock Protein 90 (HSP90 and Her2 in Adenocarcinomas of the Esophagus

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    Julia Slotta-Huspenina

    2014-06-01

    Full Text Available Her2 overexpression and amplification can be found in a significant subset of esophageal adenocarcinomas. The activity of Her2 has been shown to be modulated by molecular chaperones such as HSP90. We analyzed expression/amplification data for HSP90 and Her2 on 127 primary resected esophageal adenocarcinomas in order to evaluate a possible relationship between these two molecules. HSP90 expression determined by immunohistochemistry was observed in various levels. Thirty nine (39 tumors (30.7% were classified as Her2-positive according to their immunoreactivity and amplification status. There was a significant correlation between HSP90 expression and Her2-status (p = 0.008. This could also be demonstrated by quantitative protein expression analysis with reverse phase protein arrays (r = 0.9; p < 0.001. Her2-status was associated withpT-category (p = 0.041, lymph node metastases (p = 0.049 and tumor differentiation (p = 0.036 with a higher percentage of cases with negative Her2 status in lower tumor stagesA negative Her2-status was also associated with better survival in univariate and multivariate analysis (p = 0.001 and p = 0.014. For HSP90, no associations between clinical and pathological parameters were found. The observed association between HSP90 expression and Her2 suggests a co-regulation of these molecules in at least a subset of esophageal adenocarcinomas. Anti-HSP90 drugs, which recently have been introduced in cancer treatment, may also be an option for these tumors by targeting HSP90 alone or in combination with Her2.

  13. Evolutionary origins of Hsp90 chaperones and a deep paralogy in their bacterial ancestors.

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    Stechmann, Alexandra; Cavalier-Smith, Thomas

    2004-01-01

    The 82-90 kD family of molecular chaperone proteins has homologs in eukaryotes (Hsp90) and many eubacteria (HtpG) but not in Archaebacteria. We used representatives of all four different eukaryotic paralogs (cytosolic, endoplasmic reticulum (ER), chloroplast, mitochondrial) together with numerous eubacterial HtpG proteins for phylogenetic analyses to investigate their evolutionary origins. Our trees confirm that none of the organellar Hsp90s derives from the endosymbionts of early eukaryotes. Contrary to previous suggestions of distant origins through lateral gene transfer (LGT) all eukaryote Hsp90s are related to Gram-positive eubacterial HtpG proteins. The nucleocytosolic, ER and chloroplast Hsp90 paralogs are clearly mutually related. The origin of mitochondrial Hsp90 is more obscure, as these sequences are deeply nested within eubacteria. Our trees also reveal a deep split within eubacteria into a group of mainly long-branching sequences (including the eukaryote mitochondrial Hsp90s) and another group comprising exclusively short-branching HtpG proteins, from which the cytosolic/ER versions probably arose. Both versions are present in several eubacterial phyla, suggesting gene duplication very early in eubacterial evolution and multiple independent losses thereafter. We identified one probable case of LGT within eubacteria. However, multiple losses can simply explain the evolutionary pattern of the eubacterial HtpG paralogs and predominate over LGT. We suggest that the actinobacterial ancestor of eukaryotes harbored genes for both eubacterial HtpG paralogs, as the actinobacterium Streptomyces coelicolor still does; one could have given rise to the mitochondrial Hsp90 and the other, following another duplication event in the ancestral eukaryote, to the cytosolic and ER Hsp90 homologs.

  14. Tah1 helix-swap dimerization prevents mixed Hsp90 co-chaperone complexes

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Rhodri M. L.; Pal, Mohinder; Roe, S. Mark; Pearl, Laurence H., E-mail: laurence.pearl@sussex.ac.uk; Prodromou, Chrisostomos, E-mail: laurence.pearl@sussex.ac.uk [University of Sussex, Falmer, Brighton BN1 9RQ (United Kingdom)

    2015-05-01

    A helix swap involving the fifth helix between two adjacently bound Tah1 molecules restores the normal binding environment of the conserved MEEVD peptide of Hsp90. Dimerization also explains how other monomeric TPR-domain proteins are excluded from forming inappropriate mixed co-chaperone complexes with Hsp90 and Tah1. Specific co-chaperone adaptors facilitate the recruitment of client proteins to the Hsp90 system. Tah1 binds the C-terminal conserved MEEVD motif of Hsp90, thus linking an eclectic set of client proteins to the R2TP complex for their assembly and regulation by Hsp90. Rather than the normal complement of seven α-helices seen in other tetratricopeptide repeat (TPR) domains, Tah1 unusually consists of the first five only. Consequently, the methionine of the MEEVD peptide remains exposed to solvent when bound by Tah1. In solution Tah1 appears to be predominantly monomeric, and recent structures have failed to explain how Tah1 appears to prevent the formation of mixed TPR domain-containing complexes such as Cpr6–(Hsp90){sub 2}–Tah1. To understand this further, the crystal structure of Tah1 in complex with the MEEVD peptide of Hsp90 was determined, which shows a helix swap involving the fifth α-helix between two adjacently bound Tah1 molecules. Dimerization of Tah1 restores the normal binding environment of the bound Hsp90 methionine residue by reconstituting a TPR binding site similar to that in seven-helix-containing TPR domain proteins. Dimerization also explains how other monomeric TPR-domain proteins are excluded from forming inappropriate mixed co-chaperone complexes.

  15. Mechanistic basis for the recognition of a misfolded protein by the molecular chaperone Hsp90.

    Science.gov (United States)

    Oroz, Javier; Kim, Jin Hae; Chang, Bliss J; Zweckstetter, Markus

    2017-02-20

    The critical toxic species in over 40 human diseases are misfolded proteins. Their interaction with molecular chaperones such as Hsp90, which preferentially interacts with metastable proteins, is essential for the blocking of disease progression. Here we used nuclear magnetic resonance (NMR) spectroscopy to determine the three-dimensional structure of the misfolded cytotoxic monomer of the amyloidogenic human protein transthyretin, which is characterized by the release of the C-terminal β-strand and perturbations of the A-B loop. The misfolded transthyretin monomer, but not the wild-type protein, binds to human Hsp90. In the bound state, the Hsp90 dimer predominantly populates an open conformation, and transthyretin retains its globular structure. The interaction surface for the transthyretin monomer comprises the N-terminal and middle domains of Hsp90 and overlaps with that of the Alzheimer's-disease-related protein tau. Taken together, the data suggest that Hsp90 uses a mechanism for the recognition of aggregation-prone proteins that is largely distinct from those of other Hsp90 clients.

  16. Synthesis and evaluation of cell-permeable biotinylated PU-H71 derivatives as tumor Hsp90 probes

    Directory of Open Access Journals (Sweden)

    Tony Taldone

    2013-03-01

    Full Text Available The attachment of biotin to a small molecule provides a powerful tool in biology. Here, we present a systematic approach to identify biotinylated analogues of the Hsp90 inhibitor PU-H71 that are capable of permeating cell membranes so as to enable the investigation of Hsp90 complexes in live cells. The identified derivative 2g can isolate Hsp90 through affinity purification and, as we show, represents a unique and useful tool to probe tumor Hsp90 biology in live cells by affinity capture, flow cytometry and confocal microscopy. To our knowledge, 2g is the only reported biotinylated Hsp90 probe to have such combined characteristics.

  17. Synthesis and evaluation of cell-permeable biotinylated PU-H71 derivatives as tumor Hsp90 probes

    Science.gov (United States)

    DaGama Gomes, Erica M; Riolo, Matthew; Patel, Hardik J; Alonso-Sabadell, Raul; Zatorska, Danuta; Patel, Maulik R; Kishinevsky, Sarah

    2013-01-01

    Summary The attachment of biotin to a small molecule provides a powerful tool in biology. Here, we present a systematic approach to identify biotinylated analogues of the Hsp90 inhibitor PU-H71 that are capable of permeating cell membranes so as to enable the investigation of Hsp90 complexes in live cells. The identified derivative 2g can isolate Hsp90 through affinity purification and, as we show, represents a unique and useful tool to probe tumor Hsp90 biology in live cells by affinity capture, flow cytometry and confocal microscopy. To our knowledge, 2g is the only reported biotinylated Hsp90 probe to have such combined characteristics. PMID:23616796

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

    Science.gov (United States)

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

    2004-01-01

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

  19. Hsp90/p50cdc37 is required for mixed-lineage kinase (MLK) 3 signaling.

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    Zhang, Hua; Wu, Wei; Du, Yan; Santos, Sarah J; Conrad, Susan E; Watson, Jack T; Grammatikakis, Nicholas; Gallo, Kathleen A

    2004-05-07

    Mixed-lineage kinase 3 (MLK3) is a mitogen-activated protein kinase (MAPK) kinase kinase that activates MAPK pathways, including the c-Jun NH(2)-terminal kinase (JNK) and p38 pathways. MLK3 and its family members have been implicated in JNK-mediated apoptosis. A survey of human cell lines revealed high levels of MLK3 in breast cancer cells. To learn more about MLK3 regulation and its signaling pathways in breast cancer cells, we engineered the estrogen-responsive human breast cancer cell line, MCF-7, to stably, inducibly express FLAG epitope-tagged MLK3. FLAG.MLK3 complexes were isolated by affinity purification, and associated proteins were identified by in-gel trypsin digestion followed by liquid chromatography/tandem mass spectrometry. Among the proteins identified were heat shock protein 90alpha,beta (Hsp90) and its kinase-specific co-chaperone p50(cdc37). We show that endogenous MLK3 complexes with Hsp90 and p50(cdc37). Further experiments demonstrate that MLK3 associates with Hsp90/p50(cdc37) through its catalytic domain in an activity-independent manner. Upon treatment of MCF-7 cells with geldanamycin, an ansamycin antibiotic that inhibits Hsp90 function, MLK3 levels decrease dramatically. Furthermore, tumor necrosis factor alpha-induced activation of MLK3 and JNK in MCF-7 cells is blocked by geldanamycin treatment. Our finding that geldanamycin treatment does not affect the cellular levels of the downstream signaling components, MAPK kinase 4, MAPK kinase 7, and JNK, suggests that Hsp90/p50(cdc37) regulates JNK signaling at the MAPK kinase kinase level. Previously identified Hsp90/p50(cdc37) clients include oncoprotein kinases and protein kinases that promote cellular proliferation and survival. Our findings reveal that Hsp90/p50(cdc37) also regulates protein kinases involved in apoptotic signaling.

  20. The combination of Hsp90 inhibitor 17AAG and heavy-ion irradiation provides effective tumor control in human lung cancer cells.

    Science.gov (United States)

    Hirakawa, Hirokazu; Fujisawa, Hiroshi; Masaoka, Aya; Noguchi, Miho; Hirayama, Ryoichi; Takahashi, Momoko; Fujimori, Akira; Okayasu, Ryuichi

    2015-03-01

    Hsp90 inhibitors have become well-studied antitumor agents for their selective property against tumors versus normal cells. The combined treatment of Hsp90 inhibitor and conventional photon radiation also showed more effective tumor growth delay than radiation alone. However, little is known regarding the combined treatment of Hsp90 inhibitor and heavy-ion irradiation. In this study, SQ5 human lung tumor cells were used in vitro for clonogenic cell survival and in vivo for tumor growth delay measurement using a mouse xenograft model after 17-allylamino-17-demethoxygeldanamycin (17AAG) pretreatment and carbon ion irradiation. Repair of DNA double strand breaks (DSBs) was also assessed along with expressions of DSB repair-related proteins. Cell cycle analysis after the combined treatment was also performed. The combined treatment of 17AAG and carbon ions revealed a promising treatment option in both in vitro and in vivo studies. One likely cause of this effectiveness was shown to be the inhibition of homologous recombination repair by 17AAG. The more intensified G2 cell cycle delay was also associated with the combined treatment when compared with carbon ion treatment alone. Our findings indicate that the combination of Hsp90 inhibition and heavy-ion irradiation provides a new effective therapeutic alternative for treatment of solid tumors.

  1. A rat retinal damage model predicts for potential clinical visual disturbances induced by Hsp90 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dan, E-mail: DZhou@syntapharma.com [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Liu, Yuan; Ye, Josephine; Ying, Weiwen; Ogawa, Luisa Shin; Inoue, Takayo; Tatsuta, Noriaki; Wada, Yumiko; Koya, Keizo [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Huang, Qin [Department of Pathology and Laboratory Medicine, Veterans Affairs Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132 (United States); Bates, Richard C.; Sonderfan, Andrew J. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States)

    2013-12-01

    In human trials certain heat shock protein 90 (Hsp90) inhibitors, including 17-DMAG and NVP-AUY922, have caused visual disorders indicative of retinal dysfunction; others such as 17-AAG and ganetespib have not. To understand these safety profile differences we evaluated histopathological changes and exposure profiles of four Hsp90 inhibitors, with or without clinical reports of adverse ocular effects, using a rat retinal model. Retinal morphology, Hsp70 expression (a surrogate marker of Hsp90 inhibition), apoptotic induction and pharmacokinetic drug exposure analysis were examined in rats treated with the ansamycins 17-DMAG and 17-AAG, or with the second-generation compounds NVP-AUY922 and ganetespib. Both 17-DMAG and NVP-AUY922 induced strong yet restricted retinal Hsp70 up-regulation and promoted marked photoreceptor cell death 24 h after the final dose. In contrast, neither 17-AAG nor ganetespib elicited photoreceptor injury. When the relationship between drug distribution and photoreceptor degeneration was examined, 17-DMAG and NVP-AUY922 showed substantial retinal accumulation, with high retina/plasma (R/P) ratios and slow elimination rates, such that 51% of 17-DMAG and 65% of NVP-AUY922 present at 30 min post-injection were retained in the retina 6 h post-dose. For 17-AAG and ganetespib, retinal elimination was rapid (90% and 70% of drugs eliminated from the retina at 6 h, respectively) which correlated with lower R/P ratios. These findings indicate that prolonged inhibition of Hsp90 activity in the eye results in photoreceptor cell death. Moreover, the results suggest that the retina/plasma exposure ratio and retinal elimination rate profiles of Hsp90 inhibitors, irrespective of their chemical class, may predict for ocular toxicity potential. - Highlights: • In human trials some Hsp90 inhibitors cause visual disorders, others do not. • Prolonged inhibition of Hsp90 in the rat eye results in photoreceptor cell death. • Retina/plasma ratio and retinal

  2. An Impermeant Ganetespib Analog Inhibits Extracellular Hsp90-Mediated Cancer Cell Migration that Involves Lysyl Oxidase 2-like Protein

    Energy Technology Data Exchange (ETDEWEB)

    McCready, Jessica [Department of Natural Sciences, Assumption College, Worcester, MA 01609 (United States); Wong, Daniel S. [Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Cell and Molecular Physiology Program, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Burlison, Joseph A.; Ying, Weiwen [Synta Pharmaceuticals, Lexington, MA 02421 (United States); Jay, Daniel G., E-mail: daniel.jay@tufts.edu [Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Cell and Molecular Physiology Program, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States)

    2014-04-30

    Extracellular Hsp90 (eHsp90) activates a number of client proteins outside of cancer cells required for migration and invasion. Therefore, eHsp90 may serve as a novel target for anti-metastatic drugs as its inhibition using impermeant Hsp90 inhibitors would not affect the numerous vital intracellular Hsp90 functions in normal cells. While some eHsp90 clients are known, it is important to establish other proteins that act outside the cell to validate eHsp90 as a drug target to limit cancer spread. Using mass spectrometry we identified two precursor proteins Galectin 3 binding protein (G3BP) and Lysyl oxidase 2-like protein (LOXL2) that associate with eHsp90 in MDA-MB231 breast cancer cell conditioned media and confirmed that LOXL2 binds to eHsp90 in immunoprecipitates. We introduce a novel impermeant Hsp90 inhibitor STA-12-7191 derived from ganetespib and show that it is markedly less toxic to cells and can inhibit cancer cell migration in a dose dependent manner. We used STA-12-7191 to test if LOXL2 and G3BP are potential eHsp90 clients. We showed that while LOXL2 can increase wound healing and compensate for STA-12-7191-mediated inhibition of wound closure, addition of G3BP had no affect on this assay. These findings support of role for LOXL2 in eHsp90 stimulated cancer cell migration and provide preliminary evidence for the use of STA-12-7191 to inhibit eHsp90 to limit cancer invasion.

  3. Localization of MRP-1 to the outer mitochondrial membrane by the chaperone protein HSP90β.

    Science.gov (United States)

    Roundhill, Elizabeth; Turnbull, Doug; Burchill, Susan

    2016-05-01

    Overexpression of plasma membrane multidrug resistance-associated protein 1 (MRP-1) in Ewing's sarcoma (ES) predicts poor outcome. MRP-1 is also expressed in mitochondria, and we have examined the submitochondrial localization of MRP-1 and investigated the mechanism of MRP-1 transport and role of this organelle in the response to doxorubicin. The mitochondrial localization of MRP-1 was examined in ES cell lines by differential centrifugation and membrane solubilization by digitonin. Whether MRP-1 is chaperoned by heat shock proteins (HSPs) was investigated by immunoprecipitation, immunofluorescence microscopy, and HSP knockout using small hairpin RNA and inhibitors (apoptozole, 17-AAG, and NVPAUY). The effect of disrupting mitochondrial MRP-1-dependent efflux activity on the cytotoxic effect of doxorubicin was investigated by counting viable cell number. Mitochondrial MRP-1 is glycosylated and localized to the outer mitochondrial membrane, where it is coexpressed with HSP90. MRP-1 binds to both HSP90 and HSP70, although only inhibition of HSP90β decreases expression of MRP-1 in the mitochondria. Disruption of mitochondrial MRP-1-dependent efflux significantly increases the cytotoxic effect of doxorubicin (combination index, MRP-1 is expressed in the outer mitochondrial membrane and is a client protein of HSP90β, where it may play a role in the doxorubicin-induced resistance of ES.-Roundhill, E., Turnbull, D., Burchill, S. Localization of MRP-1 to the outer mitochondrial membrane by the chaperone protein HSP90β.

  4. Topically Applied Hsp90 Blocker 17AAG Inhibits Autoantibody-Mediated Blister-Inducing Cutaneous Inflammation.

    Science.gov (United States)

    Tukaj, Stefan; Bieber, Katja; Kleszczyński, Konrad; Witte, Mareike; Cames, Rebecca; Kalies, Kathrin; Zillikens, Detlef; Ludwig, Ralf J; Fischer, Tobias W; Kasperkiewicz, Michael

    2017-02-01

    Cell stress-inducible Hsp90 has been recognized as key player in mediating inflammatory responses. Although its systemic blockade was successfully used to treat autoimmune diseases in preclinical models, efficacy of a topical route of Hsp90 inhibitor administration has so far not been evaluated in chronic inflammatory and autoimmune-mediated dermatoses. Here, effects of the Hsp90 blocker 17-allylamino-demethoxygeldanamycin (17AAG) applied topically to the skin were determined in experimental inflammatory epidermolysis bullosa acquisita (EBA), an anti-type VII collagen autoantibody-induced blistering skin disease. Topical 17AAG ameliorated clinical disease severity when given before or during the occurrence of skin lesions without causing cutaneous or systemic toxicity in mice with antibody transfer- and immunization-induced EBA. In both EBA models and in the setting of locally induced inflammation, topical 17AAG treatment was associated with (i) reduced neutrophilic infiltrates, (ii) decreased NF-κB activation, (iii) lowered expression of matrix metalloproteinases and Flii, and (iv) induction of anti-inflammatory Hsp70 in the skin. Our results suggest that topical delivery of Hsp90 antagonists, offering the benefit of a reduced risk of systemic adverse effects of Hsp90 inhibition, may be useful for the control of EBA and possibly other related inflammatory skin disorders.

  5. Conformational diversity in the TPR domain-mediated interaction of protein phosphatase 5 with Hsp90.

    Science.gov (United States)

    Cliff, Matthew J; Harris, Richard; Barford, David; Ladbury, John E; Williams, Mark A

    2006-03-01

    Protein phosphatase 5 (Ppp5) is one of several proteins that bind to the Hsp90 chaperone via a tetratricopeptide repeat (TPR) domain. We report the solution structure of a complex of the TPR domain of Ppp5 with the C-terminal pentapeptide of Hsp90. This structure has the "two-carboxylate clamp" mechanism of peptide binding first seen in the Hop-TPR domain complexes with Hsp90 and Hsp70 peptides. However, NMR data reveal that the Ppp5 clamp is highly dynamic, and that there are multiple modes of peptide binding and mobility throughout the complex. Although this interaction is of very high affinity, relatively few persistent contacts are found between the peptide and the Ppp5-TPR domain, thus explaining its promiscuity in binding both Hsp70 and Hsp90 in vivo. We consider the possible implications of this dynamic structure for the mechanism of relief of autoinhibition in Ppp5 and for the mechanisms of TPR-mediated recognition of Hsp90 by other proteins.

  6. Hsp90 as a Gatekeeper of Tumor Angiogenesis: Clinical Promise and Potential Pitfalls

    Directory of Open Access Journals (Sweden)

    J. E. Bohonowych

    2010-01-01

    Full Text Available Tumor vascularization is an essential modulator of early tumor growth, progression, and therapeutic outcome. Although antiangiogenic treatments appear promising, intrinsic and acquired tumor resistance contributes to treatment failure. Clinical inhibition of the molecular chaperone heat shock protein 90 (Hsp90 provides an opportunity to target multiple aspects of this signaling resiliency, which may elicit more robust and enduring tumor repression relative to effects elicited by specifically targeted agents. This review highlights several primary effectors of angiogenesis modulated by Hsp90 and describes the clinical challenges posed by the redundant circuitry of these pathways. The four main topics addressed include (1 Hsp90-mediated regulation of HIF/VEGF signaling, (2 chaperone-dependent regulation of HIF-independent VEGF-mediated angiogenesis, (3 Hsp90-dependent targeting of key proangiogenic receptor tyrosine kinases and modulation of drug resistance, and (4 consideration of factors such as tumor microenvironment that pose several challenges for the clinical efficacy of anti-angiogenic therapy and Hsp90-targeted strategies.

  7. Designed hybrid TPR peptide targeting Hsp90 as a novel anticancer agent

    Directory of Open Access Journals (Sweden)

    Ohara Koji

    2011-01-01

    Full Text Available Abstract Background Despite an ever-improving understanding of the molecular biology of cancer, the treatment of most cancers has not changed dramatically in the past three decades and drugs that do not discriminate between tumor cells and normal tissues remain the mainstays of anticancer therapy. Since Hsp90 is typically involved in cell proliferation and survival, this is thought to play a key role in cancer, and Hsp90 has attracted considerable interest in recent years as a potential therapeutic target. Methods We focused on the interaction of Hsp90 with its cofactor protein p60/Hop, and engineered a cell-permeable peptidomimetic, termed "hybrid Antp-TPR peptide", modeled on the binding interface between the molecular chaperone Hsp90 and the TPR2A domain of Hop. Results It was demonstrated that this designed hybrid Antp-TPR peptide inhibited the interaction of Hsp90 with the TPR2A domain, inducing cell death of breast, pancreatic, renal, lung, prostate, and gastric cancer cell lines in vitro. In contrast, Antp-TPR peptide did not affect the viability of normal cells. Moreover, analysis in vivo revealed that Antp-TPR peptide displayed a significant antitumor activity in a xenograft model of human pancreatic cancer in mice. Conclusion These results indicate that Antp-TPR peptide would provide a potent and selective anticancer therapy to cancer patients.

  8. HSP90 inhibition downregulates thymidylate synthase and sensitizes colorectal cancer cell lines to the effect of 5FU-based chemotherapy.

    Science.gov (United States)

    Nagaraju, Ganji Purnachandra; Alese, Olatunji B; Landry, Jerome; Diaz, Roberto; El-Rayes, Bassel F

    2014-10-30

    Cell cycle progression and DNA synthesis are essential steps in cancer cell growth. Thymidylate synthase (TS) is a therapeutic target for 5FU. We tested the hypothesis that HSP90 transcriptional and functional inhibition can inhibit cell cycle progression, downregulate TS levels and sensitize colorectal cancer (CRC) cell lines to the effects of 5FU. Treatment with ganetespib (50 nM) for 24 hours inhibited cyclin D1 and pRb at the transcriptional and translational levels and induced p21, leading to G0/G1 cell cycle arrest in both CRC cell lines (HCT-116 and HT-29). This was associated with downregulation of E2F1 and its target gene TS. In addition, ganetespib inhibited PI3K/Akt and ERK signalling pathways. Similar effects were observed with HSP90 knockdown in both cell lines. Ganetespib sensitized CRC cell lines to the effects of oxaliplatin and 5FU. Similar effects were also observed in tumors from animals treated with ganetespib, oxaliplatin and 5FU. In this study, we present in vitro and animal data supporting that the targeting of HSP90 decreases CRC cell survival and proliferation. Ganetespib sensitizes CRC cell lines to the effects of 5FU-based chemotherapy. Combining HSP90 inhibitors with chemotherapy is a rational approach for future drug development in CRC.

  9. Client Proteins and Small Molecule Inhibitors Display Distinct Binding Preferences for Constitutive and Stress-Induced HSP90 Isoforms and Their Conformationally Restricted Mutants.

    Directory of Open Access Journals (Sweden)

    Thomas L Prince

    Full Text Available The two cytosolic/nuclear isoforms of the molecular chaperone HSP90, stress-inducible HSP90α and constitutively expressed HSP90β, fold, assemble and maintain the three-dimensional structure of numerous client proteins. Because many HSP90 clients are important in cancer, several HSP90 inhibitors have been evaluated in the clinic. However, little is known concerning possible unique isoform or conformational preferences of either individual HSP90 clients or inhibitors. In this report, we compare the relative interaction strength of both HSP90α and HSP90β with the transcription factors HSF1 and HIF1α, the kinases ERBB2 and MET, the E3-ubiquitin ligases KEAP1 and RHOBTB2, and the HSP90 inhibitors geldanamycin and ganetespib. We observed unexpected differences in relative client and drug preferences for the two HSP90 isoforms, with HSP90α binding each client protein with greater apparent affinity compared to HSP90β, while HSP90β bound each inhibitor with greater relative interaction strength compared to HSP90α. Stable HSP90 interaction was associated with reduced client activity. Using a defined set of HSP90 conformational mutants, we found that some clients interact strongly with a single, ATP-stabilized HSP90 conformation, only transiently populated during the dynamic HSP90 chaperone cycle, while other clients interact equally with multiple HSP90 conformations. These data suggest different functional requirements among HSP90 clientele that, for some clients, are likely to be ATP-independent. Lastly, the two inhibitors examined, although sharing the same binding site, were differentially able to access distinct HSP90 conformational states.

  10. A Hyperactive Signalosome in Acute Myeloid Leukemia Drives Addiction to a Tumor-Specific Hsp90 Species

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    Hongliang Zong

    2015-12-01

    Full Text Available Acute myeloid leukemia (AML is a heterogeneous and fatal disease with an urgent need for improved therapeutic regimens given that most patients die from relapsed disease. Irrespective of mutation status, the development of aggressive leukemias is enabled by increasing dependence on signaling networks. We demonstrate that a hyperactive signalosome drives addiction of AML cells to a tumor-specific Hsp90 species (teHsp90. Through genetic, environmental, and pharmacologic perturbations, we demonstrate a direct and quantitative link between hyperactivated signaling pathways and apoptotic sensitivity of AML to teHsp90 inhibition. Specifically, we find that hyperactive JAK-STAT and PI3K-AKT signaling networks are maintained by teHsp90 and, in fact, gradual activation of these networks drives tumors increasingly dependent on teHsp90. Thus, although clinically aggressive AML survives via signalosome activation, this addiction creates a vulnerability that can be exploited with Hsp90-directed therapy.

  11. The HSP90 inhibitor NVP-AUY922 radiosensitizes by abrogation of homologous recombination resulting in mitotic entry with unresolved DNA damage.

    Directory of Open Access Journals (Sweden)

    Shane Zaidi

    Full Text Available Heat shock protein 90 (HSP90 is a molecular chaperone responsible for the conformational maintenance of a number of client proteins that play key roles in cell cycle arrest, DNA damage repair and apoptosis following radiation. HSP90 inhibitors exhibit antitumor activity by modulating the stabilisation and activation of HSP90 client proteins. We sought to evaluate NVP-AUY922, the most potent HSP90 inhibitor yet reported, in preclinical radiosensitization studies.NVP-AUY922 potently radiosensitized cells in vitro at low nanomolar concentrations with a concurrent depletion of radioresistance-linked client proteins. Radiosensitization by NVP-AUY922 was verified for the first time in vivo in a human head and neck squamous cell carcinoma xenograft model in athymic mice, as measured by delayed tumor growth and increased surrogate end-point survival (p = <0.0001. NVP-AUY922 was shown to ubiquitously inhibit resolution of dsDNA damage repair correlating to delayed Rad51 foci formation in all cell lines tested. Additionally, NVP-AUY922 induced a stalled mitotic phenotype, in a cell line-dependent manner, in HeLa and HN5 cell lines irrespective of radiation exposure. Cell cycle analysis indicated that NVP-AUY922 induced aberrant mitotic entry in all cell lines tested in the presence of radiation-induced DNA damage due to ubiquitous CHK1 depletion, but resultant downstream cell cycle effects were cell line dependent.These results identify NVP-AUY922 as the most potent HSP90-mediated radiosensitizer yet reported in vitro, and for the first time validate it in a clinically relevant in vivo model. Mechanistic analysis at clinically achievable concentrations demonstrated that radiosensitization is mediated by the combinatorial inhibition of cell growth and survival pathways, ubiquitous delay in Rad51-mediated homologous recombination and CHK1-mediated G(2/M arrest, but that the contribution of cell cycle perturbation to radiosensitization may be cell line

  12. Expression of heat shock proteins (HSP27, HSP60, HSP70, HSP90,GRP78, GRP94) in hepatitis B virus-related hepatocellular carcinomas and dysplastic nodules

    Institute of Scientific and Technical Information of China (English)

    Seung Oe Lim; Cheol Keun Park; Sung Gyoo Park; Jun-Hi Yoo; Young Min Park; Hie-Joon Kim; Kee-Taek Jang; Jae Won Cho; Byung Chul Yoo; Gu-Hung Jung

    2005-01-01

    AIM: Expression of heat shock proteins (HSPs) is frequently up-regulated in hepatocellular carcinoma (HCC), which evolves from dysplastic nodule (DN) and early HCC to advanced HCC. However, little is known about the differential expression of HSPs in multistep hepatocarcinogenesis. It was the purpose of this study to monitor the expression of HSPs in multistep hepatocarcinogenesis and to evaluate their prognostic significance in hepatitis B virus (HBV)related HCC.METHODS: Thirty-eight HCC and 19 DN samples were obtained from 52 hepatitis B surface antigen-positive Korean patients. Immunohistochemical and dot immunoblot analyses of HSP27, HSP60, HSP70, HSP90, glucoseregulated protein (GRP)78, and GRP94 were performed and their expression at different stages of HCC development was statistically analyzed.RESULTS: Expression of HSP27, HSP70, HSP90, GRP78, and GRP94 increased along with the stepwise progression of hepatocarcinogenesis. Strong correlation was found only in GRP78 (Spearman's r= 0.802). There was a positive correlation between the expressions of GRP78, GRP94, HSP90, or HSP70 and prognostic factors of HCC. Specifically, the expression of GRP78, GRP94, or HSP90 was associated significantly with vascular invasion and intrahepatic metastasis.CONCLUSION: The expressions of HSPs are commonly up-regulated in HBV-related HCCs and GRP78 might play an important role in the stepwise progression of HBVrelated hepatocarcinogenesis. GRP78, GRP94, and HSP90 may be important prognostic markers of HBV-related HCC, strongly suggesting vascular invasion and intrahepatic metastasis.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2012-03-01

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

  15. Secretion of extracellular hsp90α via exosomes increases cancer cell motility: a role for plasminogen activation

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    Chan Doug

    2010-06-01

    Full Text Available Abstract Background Metastasis is a multi-step process that is responsible for the majority of deaths in cancer patients. Current treatments are not effective in targeting metastasis. The molecular chaperone hsp90α is secreted from invasive cancer cells and activates MMP-2 to enhance invasiveness, required for the first step in metastasis. Methods We analyzed the morphology and motility of invasive cancer cells that were treated with exogenous exosomes in the presence or absence of hsp90α. We performed mass spectrometry and immunoprecipitation to identify plasminogen as a potential client protein of extracellular hsp90α. Plasmin activation assays and migration assays were performed to test if plasminogen is activated by extracellular hsp90α and has a role in migration. Results We found that hsp90α is secreted in exosomes in invasive cancer cells and it contributes to their invasive nature. We identified a novel interaction between hsp90α and tissue plasminogen activator that together with annexin II, also found in exosomes, activates plasmin. Extracellular hsp90α promotes plasmin activation as well as increases plasmin dependent cell motility. Conclusions Our data indicate that hsp90α is released by invasive cancer cells via exosomes and implicates hsp90α in activating plasmin, a second protease that acts in cancer cell invasion.

  16. Hsp10, Hsp70, and Hsp90 immunohistochemical levels change in ulcerative colitis after therapy

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    G. Tomasello

    2011-10-01

    Full Text Available Ulcerative colitis (UC is a form of inflammatory bowel disease (IBD characterized by damage of large bowel mucosa and frequent extra-intestinal autoimmune comorbidities. The role played in IBD pathogenesis by molecular chaperones known to interact with components of the immune system involved in inflammation is unclear. We previously demonstrated that mucosal Hsp60 decreases in UC patients treated with conventional therapies (mesalazine, probiotics, suggesting that this chaperonin could be a reliable biomarker useful for monitoring response to treatment, and that it might play a role in pathogenesis. In the present work we investigated three other heat shock protein/molecular chaperones: Hsp10, Hsp70, and Hsp90. We found that the levels of these proteins are increased in UC patients at the time of diagnosis and decrease after therapy, supporting the notion that these proteins deserve attention in the study of the mechanisms that promote the development and maintenance of IBD, and as biomarkers of this disease (e.g., to monitor response to treatment at the histological level.

  17. TsDAF-21/Hsp90 is expressed in all examined stages of Trichinella spiralis

    Science.gov (United States)

    Trichinella is an important parasitic nematode of animals worldwide. Heat shock proteins are ubiquitous in nature and allow organisms to quickly respond to environmental stress. A portion of the Tsdaf-21 gene, a Caenorhabditis elegans daf-21 homologue encoding heat-shock protein 90 (Hsp90) was clone...

  18. Phase I evaluation of STA-1474, a prodrug of the novel HSP90 inhibitor ganetespib, in dogs with spontaneous cancer.

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    Cheryl A London

    Full Text Available BACKGROUND: The novel water soluble compound STA-1474 is metabolized to ganetespib (formerly STA-9090, a potent HSP90 inhibitor previously shown to kill canine tumor cell lines in vitro and inhibit tumor growth in the setting of murine xenografts. The purpose of the following study was to extend these observations and investigate the safety and efficacy of STA-1474 in dogs with spontaneous tumors. METHODS AND FINDINGS: This was a Phase 1 trial in which dogs with spontaneous tumors received STA-1474 under one of three different dosing schemes. Pharmacokinetics, toxicities, biomarker changes, and tumor responses were assessed. Twenty-five dogs with a variety of cancers were enrolled. Toxicities were primarily gastrointestinal in nature consisting of diarrhea, vomiting, inappetence and lethargy. Upregulation of HSP70 protein expression was noted in both tumor specimens and PBMCs within 7 hours following drug administration. Measurable objective responses were observed in dogs with malignant mast cell disease (n = 3, osteosarcoma (n = 1, melanoma (n = 1 and thyroid carcinoma (n = 1, for a response rate of 24% (6/25. Stable disease (>10 weeks was seen in 3 dogs, for a resultant overall biological activity of 36% (9/25. CONCLUSIONS: This study provides evidence that STA-1474 exhibits biologic activity in a relevant large animal model of cancer. Given the similarities of canine and human cancers with respect to tumor biology and HSP90 activation, it is likely that STA-1474 and ganetespib will demonstrate comparable anti-cancer activity in human patients.

  19. Hsp90 in the continuum of breast ductal carcinogenesis: Evaluation in precursors, preinvasive and ductal carcinoma lesions

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    Patsouris Effstratios

    2010-07-01

    Full Text Available Abstract Background Hsp90 (heat shock protein90 is a chaperone protein essential for preserving and regulating the function of various cellular proteins. Elevated Hsp90 expression seems to be a trait of breast cancer and may be an integral part of the coping mechanisms that cancer cells exhibit vis-à-vis stress. This manuscript tries to examine the immunohistochemical expression of Hsp90 all along the continuum of breast ductal lesions encompassing ductal hyperplasia without atypia (DHWithoutA, atypical ductal hyperplasia (ADH, ductal carcinoma in situ (DCIS and invasive ductal carcinoma (IDC. Methods Tissue specimens were taken from 30 patients with DHWithoutA, 31 patients with ADH, 51 with DCIS and 51 with IDC. Immunohistochemical assessment of Hsp90 was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. Concerning Hsp90 assessment the percentage of positive cells and the intensity were separately analyzed. Subsequently, the Allred score was calculated. Post hoc analysis on the correlations between Hsp90 Allred score and possible predictors (grade, nodal status, tumor size, ER Allred score, PR Allred score, c-erbB-2 status and triple negative status was conducted in IDC. Results Hsp90 exhibited mainly cytoplasmic immunoreactivity. Hsp90 Allred score exhibited an increasing trend along the continuum of breast ductal lesions (Spearman's rho = 0.169, p = 0.031. Compared to the adjacent normal ducts and lobules, no statistically significant differences were noted in DHwithoutA, ADH and DCIS. Hsp90 expression (intensity, positive cells, Allred score was higher in IDC, compared to the adjacent normal tissue. Higher Hsp90 expression was observed in grade 2/3 IDCs (borderline association and tumors of larger size. At the univariable analysis, higher Hsp90 expression was associated with higher ER Allred score, PR Allred score and c-erbB-2 positivity in IDC. Triple-negative IDCs exhibited

  20. Effect of electromagnetic fields at 2.45 GHz on the levels of cellular stress proteins HSP-90 and 70 in the rat thyroid; Efecto de los campos electromagneticos a 2,45 GHz sobre los niveles de proteinas de estres celular HSP-90 y 70 en el toroides de rata

    Energy Technology Data Exchange (ETDEWEB)

    Misa Agustino, M. J.; Alvarez-Folgueras, M.; Jorge-Mora, M. T.; Jorge Barreiro, F. J.; Ares Pena, F. J.; Lleiro, J.; Lopez Martin, M. E.

    2011-07-01

    In this study we analyzed the cellular stress levels achieved by heat shock proteins (HSP) 90 and 70 in rat thyroid tissue after exposure to radio waves in TWG experimental system. Parallel measurements of body stress in animals by rectal temperature probes allow us to determine whether there is any interaction between temperature increases and cellular stress.

  1. Predicting Allosteric Effects from Orthosteric Binding in Hsp90-Ligand Interactions: Implications for Fragment-Based Drug Design

    Science.gov (United States)

    Larsson, Andreas; Nordlund, Paer; Jansson, Anna; Anand, Ganesh S.

    2016-01-01

    A key question in mapping dynamics of protein-ligand interactions is to distinguish changes at binding sites from those associated with long range conformational changes upon binding at distal sites. This assumes a greater challenge when considering the interactions of low affinity ligands (dissociation constants, KD, in the μM range or lower). Amide hydrogen deuterium Exchange mass spectrometry (HDXMS) is a robust method that can provide both structural insights and dynamics information on both high affinity and transient protein-ligand interactions. In this study, an application of HDXMS for probing the dynamics of low affinity ligands to proteins is described using the N-terminal ATPase domain of Hsp90. Comparison of Hsp90 dynamics between high affinity natural inhibitors (KD ~ nM) and fragment compounds reveal that HDXMS is highly sensitive in mapping the interactions of both high and low affinity ligands. HDXMS reports on changes that reflect both orthosteric effects and allosteric changes accompanying binding. Orthosteric sites can be identified by overlaying HDXMS onto structural information of protein-ligand complexes. Regions distal to orthosteric sites indicate long range conformational changes with implications for allostery. HDXMS, thus finds powerful utility as a high throughput method for compound library screening to identify binding sites and describe allostery with important implications for fragment-based ligand discovery (FBLD). PMID:27253209

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

    Science.gov (United States)

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

    2014-09-01

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

  3. Predicting Allosteric Effects from Orthosteric Binding in Hsp90-Ligand Interactions: Implications for Fragment-Based Drug Design.

    Directory of Open Access Journals (Sweden)

    Arun Chandramohan

    2016-06-01

    Full Text Available A key question in mapping dynamics of protein-ligand interactions is to distinguish changes at binding sites from those associated with long range conformational changes upon binding at distal sites. This assumes a greater challenge when considering the interactions of low affinity ligands (dissociation constants, KD, in the μM range or lower. Amide hydrogen deuterium Exchange mass spectrometry (HDXMS is a robust method that can provide both structural insights and dynamics information on both high affinity and transient protein-ligand interactions. In this study, an application of HDXMS for probing the dynamics of low affinity ligands to proteins is described using the N-terminal ATPase domain of Hsp90. Comparison of Hsp90 dynamics between high affinity natural inhibitors (KD ~ nM and fragment compounds reveal that HDXMS is highly sensitive in mapping the interactions of both high and low affinity ligands. HDXMS reports on changes that reflect both orthosteric effects and allosteric changes accompanying binding. Orthosteric sites can be identified by overlaying HDXMS onto structural information of protein-ligand complexes. Regions distal to orthosteric sites indicate long range conformational changes with implications for allostery. HDXMS, thus finds powerful utility as a high throughput method for compound library screening to identify binding sites and describe allostery with important implications for fragment-based ligand discovery (FBLD.

  4. Experimental and Structural Testing Module to Analyze Paralogue-Specificity and Affinity in the Hsp90 Inhibitors Series

    Science.gov (United States)

    Taldone, Tony; Patel, Pallav D.; Patel, Maulik; Patel, Hardik J.; Evans, Christopher E.; Rodina, Anna; Ochiana, Stefan; Shah, Smit K.; Uddin, Mohammad; Gewirth, Daniel; Chiosis, Gabriela

    2014-01-01

    We here describe the first reported comprehensive analysis of Hsp90 paralogue affinity and selectivity in the clinical Hsp90 inhibitor chemotypes. This has been possible through the development of a versatile experimental assay based on a new FP-probe (16a) that we both describe here. The assay can test rapidly and accurately the binding affinity of all major Hsp90 chemotypes and has a testing range that spans low nanomolar to millimolar binding affinities. We couple this assay with a computational analysis that allows for rationalization of paralogue selectivity and defines not only the major binding modes that relay pan-paralogue binding or, conversely, paralogue selectivity, but also identifies molecular characteristics that impart such features. The methods developed here provide a blueprint for parsing out the contribution of the four Hsp90 paralogues to the perceived biological activity with the current Hsp90 chemotypes and set the ground for the development of paralogue selective inhibitors. PMID:23965125

  5. Expression and significance of Hsp90α and p53 in gastric cancer%胃癌中Hsp90α和p53的表达及意义

    Institute of Scientific and Technical Information of China (English)

    余慧

    2010-01-01

    目的:研究Hsp90α及p53在人胃癌组织中的表达,分析胃癌中Hsp90α和p53表达的关系.方法:应用免疫组化S-P法检测胃癌、慢性萎缩性胃炎及慢性浅表性胃炎中Hsp90α及p53的表达.结果:Hsp90α在胃癌、慢性萎缩性胃炎及慢性浅表性胃炎中的阳性率分别为70.0%(21/30)、60.0%(12/20)、30.0%(6/20).p53在胃癌、慢性萎缩性胃炎及慢性浅表性胃炎中的阳性率分别为63.3%(19/30)、10.0%(2/20)、5.0%(1/20).胃癌中Hsp90α及p53的表达明显高于慢性浅表性胃炎(P<0.05);胃癌中Hsp90α及p53表达的关系:56.7%(17/30)的胃癌Hsp90α、p53均为阳性.23.3%(7/30)的胃癌Hsp90α、p53均为阴性,13.3%(4/30)的胃癌Hsp90α阳性但p53阴性,6.7%(2/30)的胃癌p53阳性但Hsp90α阴性,Hsp90α及p53表达呈正相关(P<0.05).结论:Hsp90α及p53的表达与胃癌的发生及发展有关;胃癌组织中Hsp90α及p53表达呈正相关.

  6. Nucleotide-Free sB-Raf is Preferentially Bound by Hsp90 and Cdc37 In Vitro.

    Science.gov (United States)

    Eckl, Julia M; Daake, Marina; Schwartz, Sebastian; Richter, Klaus

    2016-10-09

    The molecular chaperone Hsp90 and its cofactor Cdc37 are required for the stability of protein kinases in the cellular environment. Upon pharmacological inhibition of Hsp90, the Hsp90-dependent kinases are degraded quickly by the proteasome. Clear physiological evidence for the formation of heterooligomeric complexes between the chaperone system and its kinase clients exist, but the mechanisms of client processing are still enigmatic. Here, we investigate the interaction of the chaperone system with a stabilized fragment of the Hsp90-dependent protein kinase B-Raf (sB-Raf). sB-Raf is aggregation prone at elevated temperatures. We find that nucleotide binding strongly stabilizes the folded state of sB-Raf and suppresses its aggregation. Also, Cdc37 and Hsp90 in combination can suppress sB-Raf aggregation while forming a ternary complex with the kinase. The presence of nucleotides leads to the dissociation of the kinase from the ternary chaperone complex, implying that the stabilization of the kinase by nucleotides reduces its affinity toward the chaperone machinery. Human Cdc37-Hsp90 complexes can bind to kinase, if the NM domain of the chaperone is present. Nematode Cdc37, which does not require the N-terminal Hsp90 domain for binding, can form a ternary complex with the MC construct of Hsp90, which lacks the aggregation propensity of sB-Raf. Like the full-length complex, this interaction is sensitive to ATP binding to sB-Raf. We thus find that the interaction between sB-Raf and the Hsp90 chaperone system is based on contacts with the M domain of Hsp90, which contributes in forming the ternary complex with CeCdc37 as long as the kinase is not stabilized by nucleotide.

  7. Targeting Hsp90 with small molecule inhibitors induces the over-expression of the anti-apoptotic molecule, survivin, in human A549, HONE-1 and HT-29 cancer cells

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    Lyu Kevin W

    2010-04-01

    Full Text Available Abstract Background Survivin is a dual functioning protein. It inhibits the apoptosis of cancer cells by inhibiting caspases, and also promotes cancer cell growth by stabilizing microtubules during mitosis. Since the molecular chaperone Hsp90 binds and stabilizes survivin, it is widely believed that down-regulation of survivin is one of the important therapeutic functions of Hsp90 inhibitors such as the phase III clinically trialed compound 17-AAG. However, Hsp90 interferes with a number of molecules that up-regulate the intracellular level of survivin, raising the question that clinical use of Hsp90 inhibitors may indirectly induce survivin expression and subsequently enhance cancer anti-drug responses. The purpose of this study is to determine whether targeting Hsp90 can alter survivin expression differently in different cancer cell lines and to explore possible mechanisms that cause the alteration in survivin expression. Results Here, we demonstrated that Hsp90 inhibitors, geldanamycin and 17-AAG, induced the over-expression of survivin in three different human cancer cell lines as shown by Western blotting. Increased survivin mRNA transcripts were observed in 17-AAG and geldanamycin-treated HT-29 and HONE-1 cancer cells. Interestingly, real-time PCR and translation inhibition studies revealed that survivin was over-expressed partially through the up-regulation of protein translation instead of gene transcription in A549 cancer cells. In addition, 17-AAG-treated A549, HONE-1 and HT-29 cells showed reduced proteasomal activity while inhibition of 26S proteasome activity further increased the amount of survivin protein in cells. At the functional level, down-regulation of survivin by siRNA further increased the drug sensitivity to 17-AAG in the tested cancer cell lines. Conclusions We showed for the first time that down-regulation of survivin is not a definite therapeutic function of Hsp90 inhibitors. Instead, targeting Hsp90 with small

  8. Effect of Root Extracts of Medicinal Herb Glycyrrhiza glabra on HSP90 Gene Expression and Apoptosis in the HT-29 Colon Cancer Cell Line.

    Science.gov (United States)

    Nourazarian, Seyed Manuchehr; Nourazarian, Alireza; Majidinia, Maryam; Roshaniasl, Elmira

    2015-01-01

    Colorectal cancer is one of the most common lethal cancer types worldwide. In recent years, widespread and large-scale studies have been done on medicinal plants for anti-cancer effects, including Glycyrrhiza glabra. The aim of this study was to evaluate the effects of an ethanol extract Glycyrrhiza glabra on the expression of HSP90, growth and apoptosis in the HT-29 colon cancer cell line. HT-29 cells were treated with different concentrations of extract (50,100,150, and 200 μg/ml). For evaluation of cell proliferation and apoptosis, we used MTT assay and flow cytometry technique, respectively. RT-PCR was also carried out to evaluate the expression levels of HSP90 genes. Results showed that Glycyrrhiza glabra inhibited proliferation of the HT-29 cell line at a concentration of 200 μg/ml and this was confirmed by the highest rate of cell death as measured by trypan blue and MTT assays. RT-PCR results showed down-regulation of HSP90 gene expression which implied an ability of Glycyrrhiza glabra to induce apoptosis in HT-29 cells and confirmed its anticancer property. Further studies are required to evaluate effects of the extract on other genes and also it is necessary to make an extensive in vivo biological evaluation and subsequently proceed with clinical evaluations.

  9. The new platinum(IV derivative LA-12 shows stronger inhibitory effect on Hsp90 function compared to cisplatin

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    Stelclova Dagmar

    2010-06-01

    Full Text Available Abstract Background Cisplatin and its derivatives are commonly used anti-cancer drugs. However, cisplatin has clinical limitations including serious side effects and frequent emergence of intrinsic or acquired resistance. Thus, the novel platinum(IV complex LA-12 represents a promising treatment modality, which shows increased intracellular penetration resulting in improved cytotoxicity in various cancer cell lines, including cisplatin resistant cells. Results LA-12 disrupts cellular proliferation regardless of the p53 status in the cells, however the potency of the drug is greatly enhanced by the presence of a functional p53, indicating several mechanisms of action. Similarly to cisplatin, an interaction of LA-12 with molecular chaperone Hsp90 was proposed. Binding of LA-12 to Hsp90 was demonstrated by Hsp90 immunoprecipitation followed by platinum measurement using atomic absorption spectrometry (AAS. An inhibitory effect of LA-12 on Hsp90 chaperoning function was shown by decrease of Hsp90-assisted wild-type p53 binding to p21WAF1 promoter sequence in vitro and by accelerated ubiqutination and degradation of primarily unfolded mutant p53 proteins in cells exposed to LA-12. Conclusions To generalize our findings, LA-12 induced degradation of other Hsp90 client proteins such as Cyclin D1 and estrogen receptor was shown and proved as more efficient in comparison with cisplatin. This newly characterised molecular mechanism of action opens opportunities to design new cancer treatment strategy profitable from unique LA-12 properties, which combine DNA damaging and Hsp90 inhibitory effects.

  10. Progesterone receptor chaperone complex-based highthroughput screening assay: identification of capsaicin as inhibitor of Hsp90 machine

    Science.gov (United States)

    Patwardhan, Chaitanya A.; Alfa, Eyad; Lu, Su; Chadli, Ahmed

    2016-01-01

    Hsp90 and its co-chaperones are known to be important for cancer cell survival. The N-terminal inhibitors of Hsp90 that are in ongoing clinical trials as anti-tumor agents have unfortunately shown disappointing efficacies in the clinic. Thus, novel inhibitors of the Hsp90 machine with different mechanism of action are urgently needed. We report here the development of a novel high-throughput drug-screening (HTS) assay platform to identify small molecule inhibitors of Hsp90 and its co-chaperones. This assay quantitatively measures the ability of Hsp90 and its co-chaperones to refold/protect the progesterone receptor (PR), a physiological client of Hsp90, in 96-well plate format. We screened the NIH clinical collection drug library and identified capsaicin as a hit molecule. Capsaicin is an FDA-approved drug for topical use in pain management. Cell survival assays showed that capsaicin selectively kills cancer cells and destabilizes several Hsp90 client proteins. Thus, our data may explain the seemingly pleotropic effect of capsaicin. PMID:25184514

  11. Involvement of yeast HSP90 isoforms in response to stress and cell death induced by acetic acid.

    Science.gov (United States)

    Silva, Alexandra; Sampaio-Marques, Belém; Fernandes, Angela; Carreto, Laura; Rodrigues, Fernando; Holcik, Martin; Santos, Manuel A S; Ludovico, Paula

    2013-01-01

    Acetic acid-induced apoptosis in yeast is accompanied by an impairment of the general protein synthesis machinery, yet paradoxically also by the up-regulation of the two isoforms of the heat shock protein 90 (HSP90) chaperone family, Hsc82p and Hsp82p. Herein, we show that impairment of cap-dependent translation initiation induced by acetic acid is caused by the phosphorylation and inactivation of eIF2α by Gcn2p kinase. A microarray analysis of polysome-associated mRNAs engaged in translation in acetic acid challenged cells further revealed that HSP90 mRNAs are over-represented in this polysome fraction suggesting preferential translation of HSP90 upon acetic acid treatment. The relevance of HSP90 isoform translation during programmed cell death (PCD) was unveiled using genetic and pharmacological abrogation of HSP90, which suggests opposing roles for HSP90 isoforms in cell survival and death. Hsc82p appears to promote survival and its deletion leads to necrotic cell death, while Hsp82p is a pro-death molecule involved in acetic acid-induced apoptosis. Therefore, HSP90 isoforms have distinct roles in the control of cell fate during PCD and their selective translation regulates cellular response to acetic acid stress.

  12. Apigenin inhibits proliferation and induces apoptosis in human multiple myeloma cells through targeting the trinity of CK2, Cdc37 and Hsp90

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    Xu Yuan-Ji

    2011-08-01

    Full Text Available Abstract Background Multiple myeloma (MM is a B-cell malignancy that is largely incurable and is characterized by the accumulation of malignant plasma cells in the bone marrow. Apigenin, a common flavonoid, has been reported to suppress proliferation in a wide variety of solid tumors and hematological cancers; however its mechanism is not well understood and its effect on MM cells has not been determined. Results In this study, we investigated the effects of apigenin on MM cell lines and on primary MM cells. Cell viability assays demonstrated that apigenin exhibited cytotoxicity against both MM cell lines and primary MM cells but not against normal peripheral blood mononuclear cells. Together, kinase assays, immunoprecipitation and western blot analysis showed that apigenin inhibited CK2 kinase activity, decreased phosphorylation of Cdc37, disassociated the Hsp90/Cdc37/client complex and induced the degradation of multiple kinase clients, including RIP1, Src, Raf-1, Cdk4 and AKT. By depleting these kinases, apigenin suppressed both constitutive and inducible activation of STAT3, ERK, AKT and NF-κB. The treatment also downregulated the expression of the antiapoptotic proteins Mcl-1, Bcl-2, Bcl-xL, XIAP and Survivin, which ultimately induced apoptosis in MM cells. In addition, apigenin had a greater effects in depleting Hsp90 clients when used in combination with the Hsp90 inhibitor geldanamycin and the histone deacetylase inhibitor vorinostat. Conclusions Our results suggest that the primary mechanisms by which apigenin kill MM cells is by targeting the trinity of CK2-Cdc37-Hsp90, and this observation reveals the therapeutic potential of apigenin in treating multiple myeloma.

  13. Synthesis and evaluation of new Hsp90 inhibitors based on a 1,4,5-trisubstituted 1,2,3-triazole scaffold.

    Science.gov (United States)

    Taddei, Maurizio; Ferrini, Serena; Giannotti, Luca; Corsi, Massimo; Manetti, Fabrizio; Giannini, Giuseppe; Vesci, Loredana; Milazzo, Ferdinando M; Alloatti, Domenico; Guglielmi, Mario B; Castorina, Massimo; Cervoni, Maria L; Barbarino, Marcella; Foderà, Rosanna; Carollo, Valeria; Pisano, Claudio; Armaroli, Silvia; Cabri, Walter

    2014-03-27

    Ruthenium catalyzed 1,3-cycloaddition (click chemistry) of an azido moiety installed on dihydroxycumene scaffold with differently substituted aryl propiolates gave a new family of 1,4,5-trisubstituted triazole carboxylic acid derivatives that showed high affinity toward Hsp90 associated with cell proliferation inhibition, both in nanomolar range. The 1,5 arrangement of the resorcinol, the aryl moieties, and the presence of an alkyl (secondary) amide in position 4 of the triazole ring were essential to get high activity. Docking simulations suggested that the triazoles penetrate the Hsp90 ATP binding site. Some 1,4,5-trisubstituted triazole carboxamides induced dramatic depletion of the examined client proteins and a very strong increase in the expression levels of the chaperone Hsp70. In vitro metabolic stability and in vivo preliminary studies on selected compounds have shown promising results comparable to the potent Hsp90 inhibitor NVP-AUY922. One of them, (compound 18, SST0287CL1) was selected for further investigation as the most promising drug candidate.

  14. Identification of the critical therapeutic entity in secreted Hsp90α that promotes wound healing in newly re-standardized healthy and diabetic pig models.

    Science.gov (United States)

    O'Brien, Kathryn; Bhatia, Ayesha; Tsen, Fred; Chen, Mei; Wong, Alex K; Woodley, David T; Li, Wei

    2014-01-01

    Chronic and non-healing skin wounds represent a significant clinical, economic and social problem worldwide. Currently, there are few effective treatments. Lack of well-defined animal models to investigate wound healing mechanisms and furthermore to identify new and more effective therapeutic agents still remains a major challenge. Pig skin wound healing is close to humans. However, standardized pig wound healing models with demonstrated validity for testing new wound healing candidates are unavailable. Here we report a systematic evaluation and establishment of both acute and diabetic wound healing models in pigs, including wound-creating pattern for drug treatment versus control, measurements of diabetic parameters and the time for detecting delayed wound healing. We find that treatment and control wounds should be on the opposite and corresponding sides of a pig. We demonstrate a strong correlation between duration of diabetic conditions and the length of delay in wound closure. Using these new models, we narrow down the minimum therapeutic entity of secreted Hsp90α to a 27-amino acid peptide, called fragment-8 (F-8). In addition, results of histochemistry and immunohistochemistry analyses reveal more organized epidermis and dermis in Hsp90α-healed wounds than the control. Finally, Hsp90α uses a similar signaling mechanism to promote migration of isolated pig and human keratinocytes and dermal fibroblasts. This is the first report that shows standardized pig models for acute and diabetic wound healing studies and proves its usefulness with both an approved drug and a new therapeutic agent.

  15. Combination of a Selective HSP90α/β Inhibitor and a RAS-RAF-MEK-ERK Signaling Pathway Inhibitor Triggers Synergistic Cytotoxicity in Multiple Myeloma Cells.

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    Rikio Suzuki

    Full Text Available Heat shock protein (HSP90 inhibitors have shown significant anti-tumor activities in preclinical settings in both solid and hematological tumors. We previously reported that the novel, orally available HSP90α/β inhibitor TAS-116 shows significant anti-MM activities. In this study, we further examined the combination effect of TAS-116 with a RAS-RAF-MEK-ERK signaling pathway inhibitor in RAS- or BRAF-mutated MM cell lines. TAS-116 monotherapy significantly inhibited growth of RAS-mutated MM cell lines and was associated with decreased expression of downstream target proteins of the RAS-RAF-MEK-ERK signaling pathway. Moreover, TAS-116 showed synergistic growth inhibitory effects with the farnesyltransferase inhibitor tipifarnib, the BRAF inhibitor dabrafenib, and the MEK inhibitor selumetinib. Importantly, treatment with these inhibitors paradoxically enhanced p-C-Raf, p-MEK, and p-ERK activity, which was abrogated by TAS-116. TAS-116 also enhanced dabrafenib-induced MM cytotoxicity associated with mitochondrial damage-induced apoptosis, even in the BRAF-mutated U266 MM cell line. This enhanced apoptosis in RAS-mutated MM triggered by combination treatment was observed even in the presence of bone marrow stromal cells. Taken together, our results provide the rationale for novel combination treatment with HSP90α/β inhibitor and RAS-RAF-MEK-ERK signaling pathway inhibitors to improve outcomes in patients with in RAS- or BRAF-mutated MM.

  16. Combination of a Selective HSP90α/β Inhibitor and a RAS-RAF-MEK-ERK Signaling Pathway Inhibitor Triggers Synergistic Cytotoxicity in Multiple Myeloma Cells.

    Science.gov (United States)

    Suzuki, Rikio; Kikuchi, Shohei; Harada, Takeshi; Mimura, Naoya; Minami, Jiro; Ohguchi, Hiroto; Yoshida, Yasuhiro; Sagawa, Morihiko; Gorgun, Gullu; Cirstea, Diana; Cottini, Francesca; Jakubikova, Jana; Tai, Yu-Tzu; Chauhan, Dharminder; Richardson, Paul G; Munshi, Nikhil; Ando, Kiyoshi; Utsugi, Teruhiro; Hideshima, Teru; Anderson, Kenneth C

    2015-01-01

    Heat shock protein (HSP)90 inhibitors have shown significant anti-tumor activities in preclinical settings in both solid and hematological tumors. We previously reported that the novel, orally available HSP90α/β inhibitor TAS-116 shows significant anti-MM activities. In this study, we further examined the combination effect of TAS-116 with a RAS-RAF-MEK-ERK signaling pathway inhibitor in RAS- or BRAF-mutated MM cell lines. TAS-116 monotherapy significantly inhibited growth of RAS-mutated MM cell lines and was associated with decreased expression of downstream target proteins of the RAS-RAF-MEK-ERK signaling pathway. Moreover, TAS-116 showed synergistic growth inhibitory effects with the farnesyltransferase inhibitor tipifarnib, the BRAF inhibitor dabrafenib, and the MEK inhibitor selumetinib. Importantly, treatment with these inhibitors paradoxically enhanced p-C-Raf, p-MEK, and p-ERK activity, which was abrogated by TAS-116. TAS-116 also enhanced dabrafenib-induced MM cytotoxicity associated with mitochondrial damage-induced apoptosis, even in the BRAF-mutated U266 MM cell line. This enhanced apoptosis in RAS-mutated MM triggered by combination treatment was observed even in the presence of bone marrow stromal cells. Taken together, our results provide the rationale for novel combination treatment with HSP90α/β inhibitor and RAS-RAF-MEK-ERK signaling pathway inhibitors to improve outcomes in patients with in RAS- or BRAF-mutated MM.

  17. Identification of the critical therapeutic entity in secreted Hsp90α that promotes wound healing in newly re-standardized healthy and diabetic pig models.

    Directory of Open Access Journals (Sweden)

    Kathryn O'Brien

    Full Text Available Chronic and non-healing skin wounds represent a significant clinical, economic and social problem worldwide. Currently, there are few effective treatments. Lack of well-defined animal models to investigate wound healing mechanisms and furthermore to identify new and more effective therapeutic agents still remains a major challenge. Pig skin wound healing is close to humans. However, standardized pig wound healing models with demonstrated validity for testing new wound healing candidates are unavailable. Here we report a systematic evaluation and establishment of both acute and diabetic wound healing models in pigs, including wound-creating pattern for drug treatment versus control, measurements of diabetic parameters and the time for detecting delayed wound healing. We find that treatment and control wounds should be on the opposite and corresponding sides of a pig. We demonstrate a strong correlation between duration of diabetic conditions and the length of delay in wound closure. Using these new models, we narrow down the minimum therapeutic entity of secreted Hsp90α to a 27-amino acid peptide, called fragment-8 (F-8. In addition, results of histochemistry and immunohistochemistry analyses reveal more organized epidermis and dermis in Hsp90α-healed wounds than the control. Finally, Hsp90α uses a similar signaling mechanism to promote migration of isolated pig and human keratinocytes and dermal fibroblasts. This is the first report that shows standardized pig models for acute and diabetic wound healing studies and proves its usefulness with both an approved drug and a new therapeutic agent.

  18. The human TPR protein TTC4 is a putative Hsp90 co-chaperone which interacts with CDC6 and shows alterations in transformed cells.

    Directory of Open Access Journals (Sweden)

    Gilles Crevel

    Full Text Available BACKGROUND: The human TTC4 protein is a TPR (tetratricopeptide repeat motif-containing protein. The gene was originally identified as being localized in a genomic region linked to breast cancer and subsequent studies on melanoma cell lines revealed point mutations in the TTC4 protein that may be associated with the progression of malignant melanoma. METHODOLOGY/PRINCIPLE FINDINGS: Here we show that TTC4 is a nucleoplasmic protein which interacts with HSP90 and HSP70, and also with the replication protein CDC6. It has significant structural and functional similarities with a previously characterised Drosophila protein Dpit47. We show that TTC4 protein levels are raised in malignant melanoma cell lines compared to melanocytes. We also see increased TTC4 expression in a variety of tumour lines derived from other tissues. In addition we show that TTC4 proteins bearing some of the mutations previously identified from patient samples lose their interaction with the CDC6 protein. CONCLUSIONS/SIGNIFICANCE: Based on these results and our previous work with the Drosophila Dpit47 protein we suggest that TTC4 is an HSP90 co-chaperone protein which forms a link between HSP90 chaperone activity and DNA replication. We further suggest that the loss of the interaction with CDC6 or with additional client proteins could provide one route through which TTC4 could influence malignant development of cells.

  19. Potential diagnostic significance of HSP90, ACS/TMS1, and L-plastin in the identification of melanoma.

    Science.gov (United States)

    Strickler, Allen G; Vasquez, Juan G; Yates, Nathan; Ho, Jonhan

    2014-12-01

    Melanoma is one of the deadliest cancers, yet it remains a diagnostic and prognostic challenge. The lack of effective treatment modalities compounds this challenge. Characterizing the molecular mechanisms leading to the development of melanoma is the first step to understanding the pathophysiology of melanoma. Numerous molecular studies have helped us understand critical changes that occur in the transition from a benign nevus to melanoma. However, many of these processes remain undiscovered. The goal of the current project was to characterize the proteomes of benign nevi and malignant melanomas using proteomic methods, with confirmation by immunohistochemical analysis. Using tandem mass spectrometry, we identified proteins potentially involved in melanoma pathogenesis. Several of the identified proteins have known roles in oncogenesis, melanogenesis, or both. We selected Hsp90-β, apoptosis-associated speck-like protein containing a CARD (ASC/TMS1), and L-plastin from these to analyze nevi and melanoma samples by immunohistochemical analysis. Hsp90-β and ASC/TMS1 staining was higher in melanoma when compared with nevi, whereas L-plastin protein expression was not significantly different between cells of these tumor types; however, it was expressed in the inflammatory milieu of melanoma. ACS/TMS1 showed staining in normal and junctional melanocytes, as well as in superficial nevomelanocytes, but deeper dermal nevomelanocytes gradually lost expression. This study helps validate the use of proteomics to aid in characterizing protein differences between nevi and melanomas and also underscores the importance of correlating proteomic results with histomorphology to understand the context of the information. The proteins in the current study may hold potential in differentiating between melanoma and benign nevi in diagnostically challenging cases.

  20. 草鱼hsp70和hsp90对温度急性变化的响应%Effect of rapid temperature change on expression of hsp70 and hsp90 in grass carp(Ctenopharyngodon idella)

    Institute of Scientific and Technical Information of China (English)

    周鑫; 董云伟; 王芳; 董双林

    2013-01-01

    Grass carp ( Ctenopharyngodon idella) is one of the most important cultured fishes in China. During transportation in summer,massive mortality often occurs. As molecular chaperones,Hsps assist cells in their recovery from stress and promote cytoprotection. Limited reports described the expression of Hsps in grass carp at high temperatures, and the relationship between oxygen consumption, expression of heat shock protein and mortality needs to be investigated based on the oxygen- and capability- limited thermal tolerance theory (OCLTT) to further elucidate the thermal adaptation of this species to high temperature in view of integrated biology. In the present study,the expressions of hsp70 and hsp90 after rapid temperature increase were studied. Grass carps were acclimated at 20 t and then exposed to designated temperatures(20,22,24, 26,28,30,32,34 ℃) for 3 h heat shock. After 2 h-recovery at 20℃, liver, muscle and gill of tested fish were sampled and hsp70 and hsp90 were determined using semi-quantitive real-time PCR. Expression of hsps increased with temperature increase until 32℃ in muscle and gill, and then decreased at 34 ℃. In liver, expression of hsps kept increasing in all temperature treatments. These results indicated that hsp70 and hsp90 were sensitive to temperature increase in grass carp. Analyzed heat shock proteins data with previous results of oxygen consumption and lethal temperatures of grass carp, the physiological adaptations of grass carp could be explained by oxygen- and capability- limited thermal tolerance theory (OCLTT), which pointed out that the imbalance between oxygen demand and tissue oxygen supply ability was the primary factor which limited organisms' thermal tolerance and the ability of aerobic metabolism greatly limited the survival of organism beyond critical temperatures. With temperature increase, the maximum value of oxygen consumption in grass carp occurred at 28 ℃, and then the oxygen consumption decreased when

  1. Involvement of YAP, TAZ and HSP90 in contact guidance and intercellular junction formation in corneal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Vijay Krishna Raghunathan

    Full Text Available The extracellular environment possesses a rich milieu of biophysical and biochemical signaling cues that are simultaneously integrated by cells and influence cellular phenotype. Yes-associated protein (YAP and transcriptional co-activator with PDZ-binding motif (WWTR1; TAZ, two important signaling molecules of the Hippo pathway, have been recently implicated as nuclear relays of cytoskeletal changes mediated by substratum rigidity and topography. These proteins intersect with other important intracellular signaling pathways (e.g. Wnt and TGFβ. In the cornea, epithelial cells adhere to the stroma through a 3-dimensional topography-rich basement membrane, with features in the nano-submicron size-scale that are capable of profoundly modulating a wide range of fundamental cell behaviors. The influences of substratum-topography, YAP/TAZ knockdown, and HSP90 inhibition on cell morphology, YAP/TAZ localization, and the expression of TGFβ2 and CTGF, were investigated. The results demonstrate (a that knockdown of TAZ enhances contact guidance in a YAP dependent manner, (b that CTGF is predominantly regulated by YAP and not TAZ, and (c that TGFβ2 is regulated by both YAP and TAZ in these cells. Additionally, inhibition of HSP90 resulted in nuclear localization and subsequent transcriptional-activation of YAP, formation of cell-cell junctions and co-localization of E-cadherin and β-catenin at adherens junctions. Results presented in this study reflect the complexities underlying the molecular relationships between the cytoskeleton, growth factors, heat shock proteins, and co-activators of transcription that impact mechanotransduction. The data reveal the importance of YAP/TAZ on the cell behaviors, and gene and protein expression.

  2. Light-dependent changes in the chick pineal temperature and the expression of cHsp90 alpha gene: a potential contribution of in vivo temperature change to the photic-entrainment of the chick pineal circadian clock.

    Science.gov (United States)

    Doi, Masao; Nakajima, Yoshito; Okano, Toshiyuki; Fukada, Yoshitaka

    2002-06-01

    The circadian clock is entrained to the diurnal alteration of environmental conditions such as light and temperature, but the molecular mechanism underlying the entrainment is not fully understood. In the present study, we employed a differential display-based screening for a set of genes that are induced by light in the chick pineal gland, a structure of the central clock entrainable to both light and temperature changes. We found that the level of the mRNA encoding chicken heat shock protein 90 alpha (cHSP90 alpha) was rapidly elevated in the pineal gland within a 5-min exposure of chicks to light. Furthermore, the pineal cHsp90 alpha mRNA was expressed rhythmically under both 12-hr light/12-hr dark (LD) cycles and constant dark (DD) conditions. The total amount of the pineal cHSP90 alpha protein was, however, kept at nearly constant levels under LD cycles, and immunohistochemical analyses of the pineal cHSP90 alpha showed invariable localization at the cytoplasm throughout the day. In vivo measurement of the chick pineal temperature demonstrated its light-dependent and time-of-day-dependent change, and the profile was very similar to that of the pineal cHSP90 alpha mRNA level. These observations suggest that the in vivo temperature change regulates the expression of temperature-responsive genes including cHSP 90 alpha in the pineal gland. The temperature change may induce a phase-shift of the pineal clock, thereby facilitating its efficient entrainment to environmental LD cycles.

  3. Down-regulation of ERK1/2 and AKT-mediated X-ray repair cross-complement group 1 protein (XRCC1) expression by Hsp90 inhibition enhances the gefitinib-induced cytotoxicity in human lung cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Tung, Chun-Liang [Department of Pathology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan (China); Jian, Yi-Jun [Department of Pathology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan (China); Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China); Syu, Jhan-Jhang; Wang, Tai-Jing; Chang, Po-Yuan; Chen, Chien-Yu; Jian, Yun-Ting [Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China); Lin, Yun-Wei, E-mail: linyw@mail.ncyu.edu.tw [Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan (China)

    2015-05-15

    Gefitinib (Iressa{sup R}, ZD1839) is a selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that blocks growth factor-mediated cell proliferation and extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT signaling activation. It has been shown that inhibition of Hsp90 function can enhance antitumor activity of EGFR-TKI. XRCC1 is an important scaffold protein in base excision repair, which could be regulated by ERK1/2 and AKT pathways. However, the role of ERK1/2 and AKT-mediated XRCC1 expression in gefitinib alone or combination with an Hsp90 inhibitor-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. In this study, gefitinib treatment decreased XRCC1 mRNA and protein expression through ERK1/2 and AKT inactivation in two NSCLC cells, A549 and H1975. Knocking down XRCC1 expression by transfection with small interfering RNA of XRCC1 enhanced the cytotoxicity and cell growth inhibition of gefitinib. Combining treatment of gefitinib with an Hsp90 inhibitor resulted in enhancing the reduction of XRCC1 protein and mRNA levels in gefitinib-exposed A549 and H1975 cells. Compared to a single agent alone, gefitinib combined with an Hsp90 inhibitor resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells. Furthermore, transfection with constitutive active MKK1 or AKT vectors rescued the XRCC1 protein level as well as the cell survival suppressed by an Hsp90 inhibitor and gefitinib. These findings suggested that down-regulation of XRCC1 can enhance the sensitivity of gefitinib for NSCLC cells. - Highlights: • Gefitinib treatment decreased XRCC1 mRNA and protein expression in NSCLC cells. • Knocking down XRCC1 expression enhanced the cytotoxic effect of gefitinib. • Gefitinib combined with an Hsp90 inhibitor resulted in synergistically cytotoxicity.

  4. Chemo-informatic design of antibiotic geldenamycin analogs to target stress proteins HSP90 of pathogenic protozoan parasites.

    Science.gov (United States)

    Singh, Chaya; Atri, Neelam

    2013-01-01

    Stress proteins HSP90 (Heat shock proteins) are essential molecular chaperones involved in signal transduction, cell cycle control, stress management, folding and degradation of proteins. HSP90 have been found in a variety of organisms including pathogens suggesting that they are ancient and conserved proteins. Here, using molecular modeling and docking protocols, antibiotic Geldenamycin and its analog are targeted to the HSP90 homolog proteins of pathogenic protozoans Plasmodium falciparum, Leishmania donovani, Trypanosoma brucei and Entamoeba Histolytica. The designed analogs of geldenamycin have shown drug like property with improved binding affinity to their targets. A decrease in insilico affinity of the analogs for the Human HSP90 target indicates that they can be used as potential drug candidates.

  5. Hsp90 inhibitors, part 1: definition of 3-D QSAutogrid/R models as a tool for virtual screening.

    Science.gov (United States)

    Ballante, Flavio; Caroli, Antonia; Wickersham, Richard B; Ragno, Rino

    2014-03-24

    The multichaperone heat shock protein (Hsp) 90 complex mediates the maturation and stability of a variety of oncogenic signaling proteins. For this reason, Hsp90 has emerged as a promising target for anticancer drug development. Herein, we describe a complete computational procedure for building several 3-D QSAR models used as a ligand-based (LB) component of a comprehensive ligand-based (LB) and structure-based (SB) virtual screening (VS) protocol to identify novel molecular scaffolds of Hsp90 inhibitors. By the application of the 3-D QSAutogrid/R method, eight SB PLS 3-D QSAR models were generated, leading to a final multiprobe (MP) 3-D QSAR pharmacophoric model capable of recognizing the most significant chemical features for Hsp90 inhibition. Both the monoprobe and multiprobe models were optimized, cross-validated, and tested against an external test set. The obtained statistical results confirmed the models as robust and predictive to be used in a subsequent VS.

  6. An interaction network predicted from public data as a discovery tool: application to the Hsp90 molecular chaperone machine.

    Directory of Open Access Journals (Sweden)

    Pablo C Echeverría

    Full Text Available Understanding the functions of proteins requires information about their protein-protein interactions (PPI. The collective effort of the scientific community generates far more data on any given protein than individual experimental approaches. The latter are often too limited to reveal an interactome comprehensively. We developed a workflow for parallel mining of all major PPI databases, containing data from several model organisms, and to integrate data from the literature for a protein of interest. We applied this novel approach to build the PPI network of the human Hsp90 molecular chaperone machine (Hsp90Int for which previous efforts have yielded limited and poorly overlapping sets of interactors. We demonstrate the power of the Hsp90Int database as a discovery tool by validating the prediction that the Hsp90 co-chaperone Aha1 is involved in nucleocytoplasmic transport. Thus, we both describe how to build a custom database and introduce a powerful new resource for the scientific community.

  7. A Novel Therapeutic Strategy for the Treatment of Glioma, Combining Chemical and Molecular Targeting of Hsp90α

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Adi; Shervington, Leroy; Munje, Chinmay; Shervington, Amal, E-mail: aashervington@googlemail.com [Brain Tumour North West, Faculty of Science and Technology, University of Central Lancashire, Preston, PR1 2HE (United Kingdom)

    2011-12-08

    Hsp90α's vital role in tumour survival and progression, together with its highly inducible expression profile in gliomas and its absence in normal tissue and cell lines validates it as a therapeutic target for glioma. Hsp90α was downregulated using the post-transcriptional RNAi strategy (sihsp90α) and a post-translational inhibitor, the benzoquinone antibiotic 17-AAG. Glioblastoma U87-MG and normal human astrocyte SVGp12 were treated with sihsp90α, 17-AAG and concurrent sihsp90α/17-AAG (combined treatment). Both Hsp90α gene silencing and the protein inhibitor approaches resulted in a dramatic reduction in cell viability. Results showed that sihsp90α, 17-AAG and a combination of sihsp90α/17-AAG, reduced cell viability by 27%, 75% and 88% (p < 0.001), respectively, after 72 h. hsp90α mRNA copy numbers were downregulated by 65%, 90% and 99% after 72 h treatment with sihsp90α, 17-AAG and sihsp90α/17-AAG, respectively. The relationship between Hsp90α protein expression and its client Akt kinase activity levels were monitored following treatment with sihsp90α, 17-AAG and sihsp90α/17-AAG. Akt kinase activity was downregulated as a direct consequence of Hsp90α inhibition. Both Hsp90α and Akt kinase levels were significantly downregulated after 72 h. Although, 17-AAG when used as a single agent reduces the Hsp90α protein and the Akt kinase levels, the efficacy demonstrated by combinatorial treatment was found to be far more effective. Combination treatment reduced the Hsp90α protein and Akt kinase levels to 4.3% and 43%, respectively, after 72 h. hsp90α mRNA expression detected in SVGp12 was negligible compared to U87-MG, also, the combination treatment did not compromise the normal cell viability. Taking into account the role of Hsp90α in tumour progression and the involvement of Akt kinase in cell signalling and the anti-apoptotic pathways in tumours, this double targets treatment infers a novel therapeutic strategy.

  8. Molecular imaging of EGFR and CD44v6 for prediction and response monitoring of HSP90 inhibition in an in vivo squamous cell carcinoma model

    Energy Technology Data Exchange (ETDEWEB)

    Spiegelberg, Diana; Mortensen, Anja C.; Stenerloew, Bo [Uppsala University, Department of Immunology, Genetics and Pathology, Uppsala (Sweden); Selvaraju, Ram K.; Eriksson, Olof [Uppsala University, Preclinical PET Platform, Uppsala (Sweden); Nestor, Marika [Uppsala University, Department of Immunology, Genetics and Pathology, Uppsala (Sweden); Uppsala University, Unit of Otolaryngology and Head and Neck Surgery, Department of Surgical Sciences, Uppsala (Sweden)

    2016-05-15

    Heat shock protein 90 (HSP90) is essential for the activation and stabilization of numerous oncogenic client proteins. AT13387 is a novel HSP90 inhibitor promoting degradation of oncogenic proteins upon binding, and may also act as a radiosensitizer. For optimal treatment there is, however, the need for identification of biomarkers for patient stratification and therapeutic response monitoring, and to find suitable targets for combination treatments. The aim of this study was to assess the response of surface antigens commonly expressed in squamous cell carcinoma to AT13387 treatment, and to find suitable biomarkers for molecular imaging and radioimmunotherapy in combination with HSP90 inhibition. Cancer cell proliferation and radioimmunoassays were used to evaluate the effect of AT13387 on target antigen expression in vitro. Inhibitor effects were then assessed in vivo in mice-xenografts. Animals were treated with AT13387 (5 x 50 mg/kg), and were imaged with PET using either {sup 18}F-FDG or {sup 124}I-labelled tracers for EGFR and CD44v6, and this was followed by ex-vivo biodistribution analysis and immunohistochemical staining. AT13387 exposure resulted in high cytotoxicity and possible radiosensitization with IC{sub 50} values below 4 nM. Both in vitro and in vivo AT13387 effectively downregulated HSP90 client proteins. PET imaging with {sup 124}I-cetuximab showed a significant decrease of EGFR in AT13387-treated animals compared with untreated animals. In contrast, the squamous cell carcinoma-associated biomarker CD44v6, visualized with {sup 124}I-AbD19384 as well as {sup 18}F-FDG uptake, were not significantly altered by AT13387 treatment. We conclude that AT13387 downregulates HSP90 client proteins, and that molecular imaging of these proteins may be a suitable approach for assessing treatment response. Furthermore, radioimmunotherapy targeting CD44v6 in combination with AT13387 may potentiate the radioimmunotherapy outcome due to radiosensitizing effects of

  9. The HSP90 Inhibitor NVP-AUY922 Radiosensitizes by Abrogation of Homologous Recombination Resulting in Mitotic Entry with Unresolved DNA Damage

    Science.gov (United States)

    Bhide, Shreerang A.; Eccles, Suzanne A.; Workman, Paul; Nutting, Christopher M.; Huddart, Robert A.; Harrington, Kevin J.

    2012-01-01

    Background Heat shock protein 90 (HSP90) is a molecular chaperone responsible for the conformational maintenance of a number of client proteins that play key roles in cell cycle arrest, DNA damage repair and apoptosis following radiation. HSP90 inhibitors exhibit antitumor activity by modulating the stabilisation and activation of HSP90 client proteins. We sought to evaluate NVP-AUY922, the most potent HSP90 inhibitor yet reported, in preclinical radiosensitization studies. Principal Findings NVP-AUY922 potently radiosensitized cells in vitro at low nanomolar concentrations with a concurrent depletion of radioresistance-linked client proteins. Radiosensitization by NVP-AUY922 was verified for the first time in vivo in a human head and neck squamous cell carcinoma xenograft model in athymic mice, as measured by delayed tumor growth and increased surrogate end-point survival (p = <0.0001). NVP-AUY922 was shown to ubiquitously inhibit resolution of dsDNA damage repair correlating to delayed Rad51 foci formation in all cell lines tested. Additionally, NVP-AUY922 induced a stalled mitotic phenotype, in a cell line-dependent manner, in HeLa and HN5 cell lines irrespective of radiation exposure. Cell cycle analysis indicated that NVP-AUY922 induced aberrant mitotic entry in all cell lines tested in the presence of radiation-induced DNA damage due to ubiquitous CHK1 depletion, but resultant downstream cell cycle effects were cell line dependent. Conclusions These results identify NVP-AUY922 as the most potent HSP90-mediated radiosensitizer yet reported in vitro, and for the first time validate it in a clinically relevant in vivo model. Mechanistic analysis at clinically achievable concentrations demonstrated that radiosensitization is mediated by the combinatorial inhibition of cell growth and survival pathways, ubiquitous delay in Rad51-mediated homologous recombination and CHK1-mediated G2/M arrest, but that the contribution of cell cycle perturbation to

  10. Role of HSP-90 for increased nNOS-mediated vasodilation in mesenteric arteries in portal hypertension

    Institute of Scientific and Technical Information of China (English)

    Lukas; Moleda; Lars; Jurzik; Matthias; Froh; Erwin; Gbele; Claus; Hellerbrand; Rainer; H; Straub; Jürgen; Schlmerich; Reiner; Wiest

    2010-01-01

    AIM:To explore the role of heat shock protein-90 (HSP-90) for nitrergic vasorelaxation in the splanchnic circulation in rats with and without portal hypertension. METHODS: Neuronal nitric oxide synthase (nNOS) and HSP-90 were analyzed by immunofluorescence, western blotting and co-immunoprecipitation in the mesenteric vasculature and isolated nerves of portal-vein-ligated (PVL) rats and sham operated rats. In vitro perfused de-endothelialized mesenteric arterial vasculature was preconstricted with norepinep...

  11. Current Understanding of HSP90 as a Novel Therapeutic Target: An Emerging Approach for the Treatment of Cancer.

    Science.gov (United States)

    Haque, Absarul; Alam, Qamre; Alam, Mohammad Zubair; Azhar, Esam I; Sait, Khalid Hussain Wali; Anfinan, Nisrin; Mushtaq, Gohar; Kamal, Mohammad Amjad; Rasool, Mahmood

    2016-01-01

    Heat Shock Protein 90 (HSP90) is a ubiquitous molecular chaperone that is considered to be the most abundantly expressed protein in various human cancers such as breast, lung, colon, prostate, leukemia and skin. The master regulator, HSP90 plays a pivotal role in the conformational stabilization, maturation and activity of its various labile oncogenic client proteins such as p53, ErbB2, Bcr-Abl, Akt, Her-2, Cdk4, Cdk6, Raf-1 and v-Src in altered cells. Hence, making a guaranteed attempt to inhibit such a master regulator for cancer therapy appears to be a potential approach for combinatorial inhibition of numerous oncogenic signaling pathways simultaneously. Considerable efforts are being under way to develop novel molecular targets and its inhibitors that may block key signaling pathways involved in the process of tumorigenesis and metastasis. In this regards, HSP90 has acquired immense interest as a potent anticancer drug-target due to its key functional link with multiple signaling pathways involved in the process of cell proliferation and cell survival. Notably, geldanamycin and its derivatives (17-AAG, 17-DMAG) have shown quite encouraging results in inhibiting HSP90 function in several cancers and currently almost 17 drug candidates known to be target HSP90 are being under clinical trials either as single agents or combinatorial therapy. Hence, this review is an attempt to get new insight into novel drug target therapy by focusing on recent advances made in understanding HSP90 chaperone structure-function relationships, identification of new HSP90 client proteins and, more importantly, on the advancements of HSP90 targeted therapy based on various existing and emerging classical inhibitors.

  12. Targeting GRP75 improves HSP90 inhibitor efficacy by enhancing p53-mediated apoptosis in hepatocellular carcinoma.

    Science.gov (United States)

    Guo, Weiwei; Yan, Lichong; Yang, Ling; Liu, Xiaoyu; E, Qiukai; Gao, Peiye; Ye, Xiaofei; Liu, Wen; Zuo, Ji

    2014-01-01

    Heat shock protein 90 (HSP90) inhibitors are potential drugs for cancer therapy. The inhibition of HSP90 on cancer cell growth largely through degrading client proteins, like Akt and p53, therefore, triggering cancer cell apoptosis. Here, we show that the HSP90 inhibitor 17-AAG can induce the expression of GRP75, a member of heat shock protein 70 (HSP70) family, which, in turn, attenuates the anti-growth effect of HSP90 inhibition on cancer cells. Additionally, 17-AAG enhanced binding of GRP75 and p53, resulting in the retention of p53 in the cytoplasm. Blocking GRP75 with its inhibitor MKT-077 potentiated the anti-tumor effects of 17-AAG by disrupting the formation of GRP75-p53 complexes, thereby facilitating translocation of p53 into the nuclei and leading to the induction of apoptosis-related genes. Finally, dual inhibition of HSP90 and GRP75 was found to significantly inhibit tumor growth in a liver cancer xenograft model. In conclusion, the GRP75 inhibitor MKT-077 enhances 17-AAG-induced apoptosis in HCCs and increases p53-mediated inhibition of tumor growth in vivo. Dual targeting of GRP75 and HSP90 may be a useful strategy for the treatment of HCCs.

  13. Targeting GRP75 improves HSP90 inhibitor efficacy by enhancing p53-mediated apoptosis in hepatocellular carcinoma.

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    Weiwei Guo

    Full Text Available Heat shock protein 90 (HSP90 inhibitors are potential drugs for cancer therapy. The inhibition of HSP90 on cancer cell growth largely through degrading client proteins, like Akt and p53, therefore, triggering cancer cell apoptosis. Here, we show that the HSP90 inhibitor 17-AAG can induce the expression of GRP75, a member of heat shock protein 70 (HSP70 family, which, in turn, attenuates the anti-growth effect of HSP90 inhibition on cancer cells. Additionally, 17-AAG enhanced binding of GRP75 and p53, resulting in the retention of p53 in the cytoplasm. Blocking GRP75 with its inhibitor MKT-077 potentiated the anti-tumor effects of 17-AAG by disrupting the formation of GRP75-p53 complexes, thereby facilitating translocation of p53 into the nuclei and leading to the induction of apoptosis-related genes. Finally, dual inhibition of HSP90 and GRP75 was found to significantly inhibit tumor growth in a liver cancer xenograft model. In conclusion, the GRP75 inhibitor MKT-077 enhances 17-AAG-induced apoptosis in HCCs and increases p53-mediated inhibition of tumor growth in vivo. Dual targeting of GRP75 and HSP90 may be a useful strategy for the treatment of HCCs.

  14. Dynamic impacts of the inhibition of the molecular chaperone Hsp90 on the T-cell proteome have implications for anti-cancer therapy.

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    Ivo Fierro-Monti

    Full Text Available The molecular chaperone Hsp90-dependent proteome represents a complex protein network of critical biological and medical relevance. Known to associate with proteins with a broad variety of functions termed clients, Hsp90 maintains key essential and oncogenic signalling pathways. Consequently, Hsp90 inhibitors are being tested as anti-cancer drugs. Using an integrated systematic approach to analyse the effects of Hsp90 inhibition in T-cells, we quantified differential changes in the Hsp90-dependent proteome, Hsp90 interactome, and a selection of the transcriptome. Kinetic behaviours in the Hsp90-dependent proteome were assessed using a novel pulse-chase strategy (Fierro-Monti et al., accompanying article, detecting effects on both protein stability and synthesis. Global and specific dynamic impacts, including proteostatic responses, are due to direct inhibition of Hsp90 as well as indirect effects. As a result, a decrease was detected in most proteins that changed their levels, including known Hsp90 clients. Most likely, consequences of the role of Hsp90 in gene expression determined a global reduction in net de novo protein synthesis. This decrease appeared to be greater in magnitude than a concomitantly observed global increase in protein decay rates. Several novel putative Hsp90 clients were validated, and interestingly, protein families with critical functions, particularly the Hsp90 family and cofactors themselves as well as protein kinases, displayed strongly increased decay rates due to Hsp90 inhibitor treatment. Remarkably, an upsurge in survival pathways, involving molecular chaperones and several oncoproteins, and decreased levels of some tumour suppressors, have implications for anti-cancer therapy with Hsp90 inhibitors. The diversity of global effects may represent a paradigm of mechanisms that are operating to shield cells from proteotoxic stress, by promoting pro-survival and anti-proliferative functions. Data are available via

  15. LPS-induced delayed preconditioning is mediated by Hsp90 and involves the heat shock response in mouse kidney.

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    Tamás Kaucsár

    Full Text Available We and others demonstrated previously that preconditioning with endotoxin (LPS protected from a subsequent lethal LPS challenge or from renal ischemia-reperfusion injury (IRI. LPS is effective in evoking the heat shock response, an ancient and essential cellular defense mechanism, which plays a role in resistance to, and recovery from diseases. Here, by using the pharmacological Hsp90 inhibitor novobiocin (NB, we investigated the role of Hsp90 and the heat shock response in LPS-induced delayed renal preconditioning.Male C57BL/6 mice were treated with preconditioning (P: 2 mg/kg, i.p. and subsequent lethal (L: 10 mg/kg, i.p. doses of LPS alone or in combination with NB (100 mg/kg, i.p.. Controls received saline (C or NB.Preconditioning LPS conferred protection from a subsequent lethal LPS treatment. Importantly, the protective effect of LPS preconditioning was completely abolished by a concomitant treatment with NB. LPS induced a marked heat shock protein increase as demonstrated by Western blots of Hsp70 and Hsp90. NB alone also stimulated Hsp70 and Hsp90 mRNA but not protein expression. However, Hsp70 and Hsp90 protein induction in LPS-treated mice was abolished by a concomitant NB treatment, demonstrating a NB-induced impairment of the heat shock response to LPS preconditioning.LPS-induced heat shock protein induction and tolerance to a subsequent lethal LPS treatment was prevented by the Hsp90 inhibitor, novobiocin. Our findings demonstrate a critical role of Hsp90 in LPS signaling, and a potential involvement of the heat shock response in LPS-induced preconditioning.

  16. Influence of Cold Stress on Transcription of HSP90 in Northeast Wild Boar Fibroblasts%冷应激对东北野猪成纤维细胞HSP90 mRNA转录水平的影响

    Institute of Scientific and Technical Information of China (English)

    李忠秋; 刘春龙; 马红; 付博; 汪亮; 彭福刚; 马建章; 刘娣

    2012-01-01

    To investigate the spatial and temporal expression profiles of HSP90 gene in fibroblasts of the Northeast Wild boar under cold stress. Real-time fluorescent quantification reverse tran-scriptase PCR (FQ-RT-PCR) was applied to analyze the expression of HSP90 mRNA in the Northeast Wild boar fibroblasts under 4,15,25 and 32 "C. The results showed that HSP90 mRNA transcription level didn't significantly increase (P>0. 05) under cold stress treatments at different temperatures; During rewarming culture, HSP90 mRNA transcription levels increased significantly (P<0. 05) within 8 h of rewarming incubation following preincubation at 4 or 15 °C and the peak showed at the 6th hour. While HSP90 mRNA transcription levels didn't increase significantly inthe 25 or 32 ℃ preincubation groups within 8 h of rewarming incubation; HSP90 mRNA transcription levels increased with decreasing of the temperature and duration of the cold treatment time when cells were preincubated at 4 or 15 ℃ for 2, 4, 6 or 8 h followed by a 4 h rewarming incubation. However, rewarming incubation didn't significantly induce transcription of HSP90 mRNA in cells preincubated at 25 or 32 ℃ for 2, 4, 6 or 8 h. The result indicated that cold stress induced increase of HSP90 mRNA transcription level in fibroblasts of the Northeast Wild boar, did not occur in the stress period during low temperature treatment, but in the cellular stress period after rewarming. Mild cold stress (25-32 ℃) didn't induce a significant increase at HSP90 mRNA transcript levels, while harsh cold stress (4-15 ℃) induced a significant increase at HSP90 mRNA transcript levels which were directly proportional to the intensity and duration of cold exposure at 4-15 ℃.·%为了揭示热休克蛋白90基因(Heat shock protein 90,HSP90)在细胞冷应激反应过程中的时空表达特性.以东北野猪成纤维细胞为研究对象,采用实时荧光定量PCR技术分析了4、15、25和32℃不同强度冷应激条件下细胞内HSP

  17. Identification and characterization of novel ER-based hsp90 gene in the red flour beetle, Tribolium castaneum.

    Science.gov (United States)

    Zhang, Yi; Gu, Shasha; Li, Chengjun; Sang, Ming; Wu, Wei; Yun, Xiaopei; Hu, Xingxing; Li, Bin

    2014-09-01

    Heat-shock protein 90 (HSP90) is a highly conserved molecular chaperone found in all species except for Archaea, which is required not only for stress tolerance but also for normal development. Recently, it was reported that HSP83, one member of the cytosolic HSP90 family, contributes to oogenesis and responds to heat resistance in Tribolium castaneum. Here, a novel ER-based HSP90 gene, Tchsp90, has been identified in T. castaneum. Phylogenetic analysis showed that hsp90s and hsp83s evolved separately from a common ancestor but that hsp90s originated earlier. Quantitative real-time polymerase chain reaction illustrated that Tchsp90 is expressed in all developmental stages and is highly expressed at early pupa and late adult stages. Tchsp90 was upregulated in response to heat stress but not to cold stress. Laval RNAi revealed that Tchsp90 is important for larval/pupal development. Meanwhile, parental RNAi indicated that it completely inhibited female fecundity and partially inhibited male fertility once Tchsp90 was knocked down and that it will further shorten the lifespan of T. castaneum. These results suggest that Tchsp90 is essential for development, lifespan, and reproduction in T. castaneum in addition to its response to heat stress.

  18. Tel2 structure and function in the Hsp90-dependent maturation of mTOR and ATR complexes

    Energy Technology Data Exchange (ETDEWEB)

    Takai, Hiroyuki; Xie, Yihu; de Lange, Titia; Pavletich, Nikola P. (Rockefeller); (SKI)

    2010-09-20

    We reported previously that the stability of all mammalian phosphatidylinositol 3-kinase-related protein kinases (PIKKs) depends on their interaction with Tel2, the ortholog of yeast Tel2 and Caenorhabditis elegans Clk-2. Here we provide evidence that Tel2 acts with Hsp90 in the maturation of PIKK complexes. Quantitative immunoblotting showed that the abundance of Tel2 is low compared with the PIKKs, and Tel2 preferentially bound newly synthesized ATM, ATR, mTOR, and DNA-PKcs. Tel2 complexes contained, in addition to Tti1-Tti2, the Hsp90 chaperone, and inhibition of Hsp90 interfered with the interaction of Tel2 with the PIKKs. Analysis of in vivo labeled nascent protein complexes showed that Tel2 and Hsp90 mediate the formation of the mTOR TORC1 and TORC2 complexes and the association of ATR with ATRIP. The structure of yeast Tel2, reported here, shows that Tel2 consists of HEAT-like helical repeats that assemble into two separate {alpha}-solenoids. Through mutagenesis, we identify a surface patch of conserved residues involved in binding to the Tti1-Tti2 complex in vitro. In vivo, mutation of this conserved patch affects cell growth, levels of PIKKs, and ATM/ATR-mediated checkpoint signaling, highlighting the importance of Tti1-Tti2 binding to the function of Tel2. Taken together, our data suggest that the Tel2-Tti1-Tti2 complex is a PIKK-specific cochaperone for Hsp90.

  19. Assessment and reconstruction of novel HSP90 genes: duplications, gains and losses in fungal and animal lineages.

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    Chrysoula N Pantzartzi

    Full Text Available Hsp90s, members of the Heat Shock Protein class, protect the structure and function of proteins and play a significant task in cellular homeostasis and signal transduction. In order to determine the number of hsp90 gene copies and encoded proteins in fungal and animal lineages and through that key duplication events that this family has undergone, we collected and evaluated Hsp90 protein sequences and corresponding Expressed Sequence Tags and analyzed available genomes from various taxa. We provide evidence for duplication events affecting either single species or wider taxonomic groups. With regard to Fungi, duplicated genes have been detected in several lineages. In invertebrates, we demonstrate key duplication events in certain clades of Arthropoda and Mollusca, and a possible gene loss event in a hymenopteran family. Finally, we infer that the duplication event responsible for the two (a and b isoforms in vertebrates occurred probably shortly after the split of Hyperoartia and Gnathostomata.

  20. The molecular chaperone Hsp90 is required for cell cycle exit in Drosophila melanogaster.

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    Jennifer L Bandura

    Full Text Available The coordination of cell proliferation and differentiation is crucial for proper development. In particular, robust mechanisms exist to ensure that cells permanently exit the cell cycle upon terminal differentiation, and these include restraining the activities of both the E2F/DP transcription factor and Cyclin/Cdk kinases. However, the full complement of mechanisms necessary to restrain E2F/DP and Cyclin/Cdk activities in differentiating cells are not known. Here, we have performed a genetic screen in Drosophila melanogaster, designed to identify genes required for cell cycle exit. This screen utilized a PCNA-miniwhite(+ reporter that is highly E2F-responsive and results in a darker red eye color when crossed into genetic backgrounds that delay cell cycle exit. Mutation of Hsp83, the Drosophila homolog of mammalian Hsp90, results in increased E2F-dependent transcription and ectopic cell proliferation in pupal tissues at a time when neighboring wild-type cells are postmitotic. Further, these Hsp83 mutant cells have increased Cyclin/Cdk activity and accumulate proteins normally targeted for proteolysis by the anaphase-promoting complex/cyclosome (APC/C, suggesting that APC/C function is inhibited. Indeed, reducing the gene dosage of an inhibitor of Cdh1/Fzr, an activating subunit of the APC/C that is required for timely cell cycle exit, can genetically suppress the Hsp83 cell cycle exit phenotype. Based on these data, we propose that Cdh1/Fzr is a client protein of Hsp83. Our results reveal that Hsp83 plays a heretofore unappreciated role in promoting APC/C function during cell cycle exit and suggest a mechanism by which Hsp90 inhibition could promote genomic instability and carcinogenesis.

  1. The molecular chaperone Hsp90 is required for cell cycle exit in Drosophila melanogaster.

    Science.gov (United States)

    Bandura, Jennifer L; Jiang, Huaqi; Nickerson, Derek W; Edgar, Bruce A

    2013-01-01

    The coordination of cell proliferation and differentiation is crucial for proper development. In particular, robust mechanisms exist to ensure that cells permanently exit the cell cycle upon terminal differentiation, and these include restraining the activities of both the E2F/DP transcription factor and Cyclin/Cdk kinases. However, the full complement of mechanisms necessary to restrain E2F/DP and Cyclin/Cdk activities in differentiating cells are not known. Here, we have performed a genetic screen in Drosophila melanogaster, designed to identify genes required for cell cycle exit. This screen utilized a PCNA-miniwhite(+) reporter that is highly E2F-responsive and results in a darker red eye color when crossed into genetic backgrounds that delay cell cycle exit. Mutation of Hsp83, the Drosophila homolog of mammalian Hsp90, results in increased E2F-dependent transcription and ectopic cell proliferation in pupal tissues at a time when neighboring wild-type cells are postmitotic. Further, these Hsp83 mutant cells have increased Cyclin/Cdk activity and accumulate proteins normally targeted for proteolysis by the anaphase-promoting complex/cyclosome (APC/C), suggesting that APC/C function is inhibited. Indeed, reducing the gene dosage of an inhibitor of Cdh1/Fzr, an activating subunit of the APC/C that is required for timely cell cycle exit, can genetically suppress the Hsp83 cell cycle exit phenotype. Based on these data, we propose that Cdh1/Fzr is a client protein of Hsp83. Our results reveal that Hsp83 plays a heretofore unappreciated role in promoting APC/C function during cell cycle exit and suggest a mechanism by which Hsp90 inhibition could promote genomic instability and carcinogenesis.

  2. Discovery of NMS-E973 as novel, selective and potent inhibitor of heat shock protein 90 (Hsp90).

    Science.gov (United States)

    Brasca, Maria Gabriella; Mantegani, Sergio; Amboldi, Nadia; Bindi, Simona; Caronni, Dannica; Casale, Elena; Ceccarelli, Walter; Colombo, Nicoletta; De Ponti, Anna; Donati, Daniele; Ermoli, Antonella; Fachin, Gabriele; Felder, Eduard R; Ferguson, Ronald D; Fiorelli, Claudio; Guanci, Marco; Isacchi, Antonella; Pesenti, Enrico; Polucci, Paolo; Riceputi, Laura; Sola, Francesco; Visco, Carlo; Zuccotto, Fabio; Fogliatto, Gianpaolo

    2013-11-15

    Novel small molecule inhibitors of heat shock protein 90 (Hsp90) were discovered with the help of a fragment based drug discovery approach (FBDD) and subsequent optimization with a combination of structure guided design, parallel synthesis and application of medicinal chemistry principles. These efforts led to the identification of compound 18 (NMS-E973), which displayed significant efficacy in a human ovarian A2780 xenograft tumor model, with a mechanism of action confirmed in vivo by typical modulation of known Hsp90 client proteins, and with a favorable pharmacokinetic and safety profile.

  3. P-glycoprotein (P-gp)-mediated efflux limits intestinal absorption of the Hsp90 inhibitor SNX-2112 in rats.

    Science.gov (United States)

    Liu, Hongming; Sun, Hua; Wu, Zhufeng; Zhang, Xingwang; Wu, Baojian

    2014-08-01

    1. The promising anticancer agent SNX-2112 (a novel Hsp90 inhibitor) is poorly bioavailable after oral administration. Here, we aim to determine the role of P-glycoprotein (P-gp) in the intestinal absorption of SNX-2112. 2. We found that SNX-2112 significantly stimulated P-gp ATPase activity in in vitro ATPase assay with a small EC50 (the half-maximal effective concentration) value of 0.32 µM. 3. In the single-pass perfused rat intestine model, absorption of SNX-2112 was not favored in the small intestine with a [Formula: see text] (the wall permeability) value of 0.38-0.64. By contrast, the compound was well absorbed in the colon with a [Formula: see text] value of 1.19. The P-gp inhibitors cyclosporine and elacridar (i.e. GF120918A) markedly enhanced SNX-2112 absorption in all four intestinal segments (i.e. duodenum, jejunum, ileum and colon) and the fold change ranged from 3.1 to 14.1. Pharmacokinetic study revealed that cyclosporine increased the systemic exposure of SNX-2112 by a 2.5-fold after oral administration. 4. This is the first report that P-gp-mediated efflux is a limiting factor for intestinal absorption of SNX-2112 in rats.

  4. Hsp90 interacts specifically with viral RNA and differentially regulates replication initiation of Bamboo mosaic virus and associated satellite RNA.

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    Ying Wen Huang

    Full Text Available Host factors play crucial roles in the replication of plus-strand RNA viruses. In this report, a heat shock protein 90 homologue of Nicotiana benthamiana, NbHsp90, was identified in association with partially purified replicase complexes from BaMV-infected tissue, and shown to specifically interact with the 3' untranslated region (3' UTR of BaMV genomic RNA, but not with the 3' UTR of BaMV-associated satellite RNA (satBaMV RNA or that of genomic RNA of other viruses, such as Potato virus X (PVX or Cucumber mosaic virus (CMV. Mutational analyses revealed that the interaction occurs between the middle domain of NbHsp90 and domain E of the BaMV 3' UTR. The knockdown or inhibition of NbHsp90 suppressed BaMV infectivity, but not that of satBaMV RNA, PVX, or CMV in N. benthamiana. Time-course analysis further revealed that the inhibitory effect of 17-AAG is significant only during the immediate early stages of BaMV replication. Moreover, yeast two-hybrid and GST pull-down assays demonstrated the existence of an interaction between NbHsp90 and the BaMV RNA-dependent RNA polymerase. These results reveal a novel role for NbHsp90 in the selective enhancement of BaMV replication, most likely through direct interaction with the 3' UTR of BaMV RNA during the initiation of BaMV RNA replication.

  5. High level prokaryotic expression and identification of heat shock protein 90 in Exopalaemon carinicauda%脊尾白虾热休克蛋白HSP90基因的原核表达与鉴定

    Institute of Scientific and Technical Information of China (English)

    韩俊英; 李健; 李吉涛; 陈萍; 李华

    2011-01-01

    The aim of this study was to set up a high level prokaryotic expression of heat shock protein 90(HSP90) of Exopalaemon carinicauda in E. Coli Rosetta. The HSP90 gene of E. Carinicauda was cloned into prokaryotic expression vector pET-30a, which was confirmed by double-endonuclease digestion and DNA sequencing. The recombinant vector was transformed into E. Coli Rosetta and was induced to express under different temperatures, durations, IPTG concentrations and OD600. The expressed product was identified by SDS-PAGE and an 82. 7 kD protein (determined by mass spectrometry) was found. The expression level varied under different conditions. The optimal expression was achieved under induction conditions of 1 mmol/L IPTG,37℃ , OD600 = 0. 58, and 7 h.%将脊尾白虾热休克蛋白90基因克隆到原核表达载体pET-30a中,经酶切验证和DNA测序鉴定后,将重组质粒转化表达宿主大肠杆菌Rosetta,优化温度、时间、IPTG和OD600表达条件进行诱导表达,收集茵液,进行SDS-PAGE和质谱检测,并用Quantity one软件分析蛋白表达水平.结果表明,成功构建了含脊尾白虾HSP90基因的重组表达载体pET-30a-HSP90,表达目的蛋白相对分子量为82.7kD,为HSP90蛋白.通过条件优化认为重组菌株Rosetta/pET-30a-HSP90的最佳诱导温度为37℃,最佳IPTG浓度为1.0 mmol/L,最佳诱导时机和诱导时间分别为0.58 h、7h.

  6. The synthetic heat shock protein 90 (Hsp90) inhibitor EC141 induces degradation of Bcr-Abl p190 protein and apoptosis of Ph-positive acute lymphoblastic leukemia cells.

    Science.gov (United States)

    Tong, Wei-Gang; Estrov, Zeev; Wang, Yongtao; O'Brien, Susan; Faderl, Stefan; Harris, David M; Van Pham, Quin; Hazan-Halevy, Inbal; Liu, Zhiming; Koch, Patricia; Kantarjian, Hagop; Keating, Michael J; Ferrajoli, Alessandra

    2011-12-01

    The prognosis of patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is poor. Chemotherapy is rarely curative and tyrosine kinase inhibitors (TKIs) induce only transient responses. Heat shock protein 90 (Hsp90) is a chaperone protein that is important in signal transduction, cell cycle control, and transcription regulation in both normal and leukemia cells. In the current study, we tested the growth inhibitory and apoptotic effects of a novel Hsp90 inhibitor, EC141 on the Ph+ ALL lines Z-119, Z-181, and Z-33, as well as primary bone marrow-derived blasts from patients with newly diagnosed Ph+ ALL. We found that EC141 inhibited the growth of Ph+ ALL cells in a concentration-dependent manner with IC(50) ranged from 1 to 10 nM. EC141 also inhibited the proliferation of primary bone marrow-derived blasts using the ALL blast colony assay. EC141 down-regulated Hsp90 and up-regulated Hsp70 protein levels, inhibited CrkL phosphorylation, and induced degradation of Bcr-Abl p190 protein through ubiquitin-dependent proteasomal pathway. Furthermore, exposure of Ph+ ALL cells to EC141 resulted in activation of caspase-3, cleavage of poly (ADP-ribose) polymerase (PARP), and induction of apoptosis. In conclusion, our data suggest that EC141 is a potent Hsp90 inhibitor with activity against Ph+ ALL. Further studies to investigate the anticancer effect of EC141 either as a single agent, or in combination in Ph+ ALL and other hematological malignancies are warranted.

  7. [The role of heat shock proteins HSP90 in the response of immune cells to centimeter microwaves].

    Science.gov (United States)

    Glushkova, O V; Novoselova, E G; Khrenov, M O; Novoselova, T V; Cherenkov, D A; Lunin, S M; Fesenko, E E

    2008-01-01

    The effects of low-level electromagnetic waves (8.15-18 GHz, 1 microW/cm2, 1 h) on the production of heat shock proteins, several cytokines, and nitric oxide in isolated mouse macrophages and lymphocytes were examined both under normal conditions and after the treatment of the cells with geldanamycin (GA), a depressor of activity of the heat shock protein 90 (Hsp90). The irradiation of cells without GA induced the production of Hsp70, nitric oxide (NO), interleukin-1beta (IL-1beta), interleukin-10 (IL-10), and the tumor necrosis factor -alpha (TNF-alpha). No changes in the production of Hsp90 in irradiated cells were observed, but intracellular locations of Hsp25 and Hsp70 altered. The preliminary treatment of cells with GA did not remove the effects of microwaves: in these conditions, the synthesis of all cytokines tested, nitric oxide, as well as total and membrane amount of Hsp70, and the amount of Hsp25 in the cytoplasm and cytoskeleton increased. Moreover, the exposure of cells incubated with GA resulted in the reduction of Hsp90-alpha production.

  8. Role of ARF6, Rab11 and external Hsp90 in the trafficking and recycling of recombinant-soluble Neisseria meningitidis adhesin A (rNadA in human epithelial cells.

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    Giuseppe Bozza

    Full Text Available Neisseria meningitidis adhesin A (NadA is a meningococcus surface protein thought to assist in the adhesion of the bacterium to host cells. We have previously shown that NadA also promotes bacterial internalization in a heterologous expression system. Here we have used the soluble recombinant NadA (rNadA lacking the membrane anchor region to characterize its internalization route in Chang epithelial cells. Added to the culture medium, rNadA internalizes through a PI3K-dependent endocytosis process not mediated by the canonical clathrin or caveolin scaffolds, but instead follows an ARF6-regulated recycling pathway previously described for MHC-I. The intracellular pool of rNadA reaches a steady state level within one hour of incubation and colocalizes in endocytic vesicles with MHC-I and with the extracellularly labeled chaperone Hsp90. Treatment with membrane permeated and impermeable Hsp90 inhibitors 17-AAG and FITC-GA respectively, lead to intracellular accumulation of rNadA, strongly suggesting that the extracellular secreted pool of the chaperone is involved in rNadA intracellular trafficking. A significant number of intracellular vesicles containing rNadA recruit Rab11, a small GTPase associated to recycling endosomes, but do not contain transferrin receptor (TfR. Interestingly, cell treatment with Hsp90 inhibitors, including the membrane-impermeable FITC-GA, abolished Rab11-rNadA colocalization but do not interfere with Rab11-TfR colocalization. Collectively, these results are consistent with a model whereby rNadA internalizes into human epithelial cells hijacking the recycling endosome pathway and recycle back to the surface of the cell via an ARF6-dependent, Rab11 associated and Hsp90-regulated mechanism. The present study addresses for the first time a meningoccoccal adhesin mechanism of endocytosis and suggests a possible entry pathway engaged by N. meningitidis in primary infection of human epithelial cells.

  9. A compound that inhibits the HOP-Hsp90 complex formation and has unique killing effects in breast cancer cell lines.

    Science.gov (United States)

    Pimienta, Genaro; Herbert, Kristina M; Regan, Lynne

    2011-12-05

    The chaperone Hsp90 is required for the correct folding and maturation of certain "client proteins" within all cells. Hsp90-mediated folding is particularly important in cancer cells, because upregulated or mutant oncogenic proteins are often Hsp90 clients. Hsp90 inhibitors thus represent a route to anticancer agents that have the potential to be active against several different types of cancer. Currently, various Hsp90 inhibitors that bind to Hsp90 at its ATP-binding site are in preclinical and clinical trials. Some of the most promising Hsp90 ATP-binding site inhibitors are the well characterized geldanamycin derivative 17-AAG and the recently described compounds PU-H71 and NVP-AUY922. An undesirable characteristic of these compounds is the transcriptional upregulation of Hsp70 that has prosurvival effects. Here we characterize the activity of a new type of chaperone inhibitor, 1,6-dimethyl-3-propylpyrimido[5,4-e][1,2,4]triazine-5,7-dione (named C9 for simplicity). Using purified protein components in vitro, C9 prevents Hsp90 from interacting with the cochaperone HOP and is thus expected to impair the Hsp90-dependent folding pathway in vivo. We show that this compound is effective in killing various breast cancer cell lines including the highly metastatic MDA-MB-231. An important property of this compound is that it does not induce the transcriptional upregulation of Hsp70. Moreover, when cells are treated with a combination of C9 and either 17-AAG or NVP-AUY922, the overexpression of Hsp70 is counteracted considerably and C9's lethal-IC50 decreases compared to its value when added alone.

  10. 一种新型Hsp90抑制剂的合成及其抑制活性%Synthesis of Novel Hsp90 Inhibotor and Its Inhibition

    Institute of Scientific and Technical Information of China (English)

    张晓颖; 张杰; 李伟; 王小龙

    2011-01-01

    对氨基苯甲酸经重氮化后再与2-氯乙酰乙酸乙醅反应制得(Z)4-[2-(1-氯-2-乙氧基-2-羰亚甲基)肼基]苯甲酸(1);1与二甲基环己二酮成环后再与对羟基环己胺完成酰胺化反应合成了一种新型Hs90抑制剂——N-(4-羟基环己基)-4-[1-(6,6-二甲基-4-氧-3-乙酰氧基-4,5,6,7-四氢吲唑)]苯甲酰胺(3),其结构经1 H NMR表征.荧光偏振法研究结果表明3对Hsp90α具有明显的抑制活性.%(Z)-4-[2-(l-chloro-2-ethoxy-2-oxoethylidene)hydrazinyl]benzoic acid(l) was prepared from p-aminobenzoic acid by diazotization, then reacted with ethyl 2-chloro-acetoacetate. A novel Hsp90 inhibotor, ethyl l-{4-[ (4-hydroxycyclohexyl)carbamoyl]phenyl} -6,6-dimethyl-4-oxo-4,5,6, 7-tetrahydro-lH-indazole-3-carboxylate(3), was synthesized by cyclization between 1 and 5,5-dime-thyl-cyclohexane-1,3-dione, then amidation with p-hydroxyl-cyclohexylamine. The structure was characterized by ' H NMR. The result from fluorescence polarization showed that 3 exhibited good inhibition against Hsp90a.

  11. In silico identification of carboxylate clamp type tetratricopeptide repeat proteins in Arabidopsis and rice as putative co-chaperones of Hsp90/Hsp70.

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    Bishun D Prasad

    Full Text Available The essential eukaryotic molecular chaperone Hsp90 operates with the help of different co-chaperones, which regulate its ATPase activity and serve as adaptors to recruit client proteins and other molecular chaperones, such as Hsp70, to the Hsp90 complex. Several Hsp90 and Hsp70 co-chaperones contain the tetratricopeptide repeat (TPR domain, which interacts with the highly conserved EEVD motif at the C-terminal ends of Hsp90 and Hsp70. The acidic side chains in EEVD interact with a subset of basic residues in the TPR binding pocket called a 'carboxylate clamp'. Since the carboxylate clamp residues are conserved in the TPR domains of known Hsp90/Hsp70 co-chaperones, we carried out an in silico search for TPR proteins in Arabidopsis and rice comprising of at least one three-motif TPR domain with conserved amino acid residues required for Hsp90/Hsp70 binding. This approach identified in Arabidopsis a total of 36 carboxylate clamp (CC-TPR proteins, including 24 novel proteins, with potential to interact with Hsp90/Hsp70. The newly identified CC-TPR proteins in Arabidopsis and rice contain additional protein domains such as ankyrin, SET, octicosapeptide/Phox/Bem1p (Phox/PB1, DnaJ-like, thioredoxin, FBD and F-box, and protein kinase and U-box, indicating varied functions for these proteins. To provide proof-of-concept of the newly identified CC-TPR proteins for interaction with Hsp90, we demonstrated interaction of AtTPR1 and AtTPR2 with AtHsp90 in yeast two-hybrid and in vitro pull down assays. These findings indicate that the in silico approach used here successfully identified in a genome-wide context CC-TPR proteins with potential to interact with Hsp90/Hsp70, and further suggest that the Hsp90/Hsp70 system relies on TPR co-chaperones more than it was previously realized.

  12. Co-crystalization and in vitro biological characterization of 5-aryl-4-(5-substituted-2-4-dihydroxyphenyl-1,2,3-thiadiazole Hsp90 inhibitors.

    Directory of Open Access Journals (Sweden)

    Swee Y Sharp

    Full Text Available A potential therapeutic strategy for targeting cancer that has gained much interest is the inhibition of the ATP binding and ATPase activity of the molecular chaperone Hsp90. We have determined the structure of the human Hsp90α N-terminal domain in complex with a series of 5-aryl-4-(5-substituted-2-4-dihydroxyphenyl-1,2,3-thiadiazoles. The structures provide the molecular details for the activity of these inhibitors. One of these inhibitors, ICPD 34, causes a structural change that affects a mobile loop, which adopts a conformation similar to that seen in complexes with ADP, rather than the conformation generally seen with the pyrazole/isoxazole-resorcinol class of inhibitors. Competitive binding to the Hsp90 N-terminal domain was observed in a biochemical assay, and these compounds showed antiproliferative activity and induced apoptosis in the HCT116 human colon cancer cell line. These inhibitors also caused induction of the heat shock response with the upregulation of Hsp72 and Hsp27 protein expression and the depletion of Hsp90 clients, CRAF, ERBB2 and CDK4, thus confirming that antiproliferative activity was through the inhibition of Hsp90. The presence of increased levels of the cleavage product of PARP indicated apoptosis in response to Hsp90 inhibitors. This work provides a framework for the further optimization of thiadiazole inhibitors of Hsp90. Importantly, we demonstrate that the thiadiazole inhibitors display a more limited core set of interactions relative to the clinical trial candidate NVP-AUY922, and consequently may be less susceptible to resistance derived through mutations in Hsp90.

  13. HSP90 gene expression induced by aspirin is associated with damage remission in a chicken myocardial cell culture exposed to heat stress.

    Science.gov (United States)

    Zhang, X; Qian, Z; Zhu, H; Tang, S; Wu, D; Zhang, M; Kemper, N; Hartung, J; Bao, E

    2016-08-01

    To understand the potential protection of heat shock protein 90 (HSP90) induced by aspirin against heat stress damage in chicken myocardial cells, enzyme activities related to stress damage, cytopathological changes, the expression and distribution of HSP90, and HSP90 mRNA levels in the myocardial cells exposed to heat stress (42°C) for different durations with or without aspirin administration (1 mg/ml, 2 h prior) in vitro were investigated. Significant increase of enzyme levels in the supernatant of heat-stressed myocardial cells and cellular lesions characterised by acute degeneration, karyopyknosis and karyorrhexis were observed, compared to non-treated cells. However, the lesions of cells treated with aspirin were milder, characterised by earlier recovery of enzyme levels to the control levels and no obvious heat stress-related cellular necrosis. Stronger positive signals in the cytoplasm and longer retention of HSP90 signal in nuclei were observed in aspirin-treated myocardial cells than those of only heat-stressed cells. HSP90 level in the aspirin-treated myocardial cells was 11.1-fold higher than that in non-treated cells, and remained at a high level at the early stage of heat stress, whereas it was just 4.1-fold higher in only heat-stressed cells and returned rapidly to a low level. Overexpression of HSP90 mRNA in aspirin-treated cells was observed throughout the experiment, whereas HSP90 mRNA decreased significantly only in heat-stressed cells. The early higher HSP90 expression induced by aspirin during heat stress was accompanied by decreased heat stress damage, suggesting that aspirin might play an important role in preventing myocardial cells from heat stress damage in vitro.

  14. Role of the HSP90-associated cochaperone p23 in enhancing activity of the androgen receptor and significance for prostate cancer.

    Science.gov (United States)

    Reebye, Vikash; Querol Cano, Laia; Lavery, Derek N; Brooke, Greg N; Powell, Sue M; Chotai, Deepa; Walker, Marjorie M; Whitaker, Hayley C; Wait, Robin; Hurst, Helen C; Bevan, Charlotte L

    2012-10-01

    Prostate tumor growth initially depends on androgens, which act via the androgen receptor (AR). Despite androgen ablation therapy, tumors eventually progress to a castrate-resistant stage in which the AR remains active. The mechanisms are poorly understood but it may be that changes in levels or activity of AR coregulators affect trafficking and activation of the receptor. A key stage in AR signaling occurs in the cytoplasm, where unliganded receptor is associated with the heat shock protein (HSP)90 foldosome complex. p23, a key component of this complex, is best characterized as a cochaperone for HSP90 but also has HSP90-independent activity and has been reported as having differential effects on the activity of different steroid receptors. Here we report that p23 increases activity of the AR, and this appears to involve steps both in the cytoplasm (increasing ligand-binding capacity, possibly via direct interaction with AR) and the nucleus (enhancing AR occupancy at target promoters). We show, for the first time, that AR and p23 can interact, perhaps directly, when HSP90 is not present in the same complex. The effects of p23 on AR activity are at least partly HSP90 independent because a mutant form of p23, unable to bind HSP90, nevertheless increases AR activity. In human prostate tumors, nuclear p23 was higher in malignant prostate cells compared with benign/normal cells, supporting the utility of p23 as a therapeutic target in prostate cancer.

  15. Destabilization of PDK1 by Hsp90 inactivation suppresses hepatitis C virus replication through inhibition of PRK2-mediated viral RNA polymerase phosphorylation.

    Science.gov (United States)

    Kim, Mi-Gyeong; Moon, Jae-Su; Kim, Eun-Jung; Lee, Seung-Hoon; Oh, Jong-Won

    2012-04-27

    Heat shock protein 90 (Hsp90), which chaperones multiple client proteins, has been shown to be implicated in HCV replication. Pharmacological inhibitors of Hsp90 display an anti-HCV activity. However, little is known about the mechanisms of regulation of HCV replication by Hsp90. Here, we show that Hsp90 inhibition by 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG) destabilizes phosphoinositide-dependent kinase-1 (PDK1), an upstream kinase of the protein kinase C-related kinase 2 (PRK2) responsible for phosphorylation of HCV RNA polymerase, through the proteosome pathway. Destabilization of PDK1 led to inhibition of phosphorylation of the viral RNA polymerase through a decrease in the abundance of active form PRK2 level. Consequently, Hsp90 inhibition resulted in suppression of HCV replication both in human hepatoma Huh7 cells harboring an HCV subgenomic replicon and in HCV-infected cells. 17-DMAG treatment did not interfere with HCV internal ribosome entry site-mediated translation and the cell cycle in Huh7 cells. Co-treatment of 17-DMAG with interferon-α or HA1077, an inhibitor of PRK2, enhanced the anti-HCV activity of 17-DMAG. Taken together, these findings suggest that Hsp90 plays a critical role in the regulation of HCV RNA polymerase phosphorylation via the PDK1-PRK2 signaling pathway.

  16. 水稻热激蛋白基因HSP90转化大豆的研究%Transformation of Heat Shock Protein Gene HSP90 of Rice into Soybean

    Institute of Scientific and Technical Information of China (English)

    于志晶; 尚丽霞; 蔡勤安; 孟凡钢; 马瑞

    2016-01-01

    由于干旱和盐碱化的严重影响,我国大豆生产受到很大限制.为了提高大豆的抗旱性,培育抗旱转基因大豆新品种,利用农杆菌介导的子叶节遗传转化技术体系,首次将水稻热激蛋白基因HSP90导入大豆受体材料Bert中,通过HSP90在大豆中过表达,获得了耐旱转基因大豆新材料.本试验中4 000个子叶节外植体用于遗传转化,再生转化苗经PCR和Southern杂交鉴定结合PPT抗性筛选(bar为筛选标记),共获得128棵阳性转基因植株,转化率为3.2%.经初步筛选,获得15份耐旱性较好的材料,其耐旱性显著优于对照.研究结果为进一步筛选耐旱转基因大豆新材料奠定了较好的基础.

  17. Inhibition of HSP90 by AUY922 Preferentially Kills Mutant KRAS Colon Cancer Cells by Activating Bim through ER Stress.

    Science.gov (United States)

    Wang, Chun Yan; Guo, Su Tang; Wang, Jia Yu; Liu, Fen; Zhang, Yuan Yuan; Yari, Hamed; Yan, Xu Guang; Jin, Lei; Zhang, Xu Dong; Jiang, Chen Chen

    2016-03-01

    Oncogenic mutations of KRAS pose a great challenge in the treatment of colorectal cancer. Here we report that mutant KRAS colon cancer cells are nevertheless more susceptible to apoptosis induced by the HSP90 inhibitor AUY922 than those carrying wild-type KRAS. Although AUY922 inhibited HSP90 activity with comparable potency in colon cancer cells irrespective of their KRAS mutational statuses, those with mutant KRAS were markedly more sensitive to AUY922-induced apoptosis. This was associated with upregulation of the BH3-only proteins Bim, Bik, and PUMA. However, only Bim appeared essential, in that knockdown of Bim abolished, whereas knockdown of Bik or PUMA only moderately attenuated apoptosis induced by AUY922. Mechanistic investigations revealed that endoplasmic reticulum (ER) stress was responsible for AUY922-induced upregulation of Bim, which was inhibited by a chemical chaperone or overexpression of GRP78. Conversely, siRNA knockdown of GRP78 or XBP-1 enhanced AUY922-induced apoptosis. Remarkably, AUY922 inhibited the growth of mutant KRAS colon cancer xenografts through activation of Bim that was similarly associated with ER stress. Taken together, these results suggest that AUY922 is a promising drug in the treatment of mutant KRAS colon cancers, and the agents that enhance the apoptosis-inducing potential of Bim may be useful to improve the therapeutic efficacy.

  18. Hsp90 inhibition suppresses NF-κB transcriptional activation via Sirt-2 in human lung microvascular endothelial cells.

    Science.gov (United States)

    Thangjam, Gagan S; Birmpas, Charalampos; Barabutis, Nektarios; Gregory, Betsy W; Clemens, Mary Ann; Newton, Joseph R; Fulton, David; Catravas, John D

    2016-05-15

    The ability of anti-heat shock protein 90 (Hsp90) drugs to attenuate NF-κB-mediated transcription is the major basis for their anti-inflammatory properties. While the molecular mechanisms underlying this effect are not clear, they appear to be distinct in human endothelial cells. We now show for the first time that type 2 sirtuin (Sirt-2) histone deacetylase binds human NF-κB target gene promoter and prevents the recruitment of NF-κB proteins and subsequent assembly of RNA polymerase II complex in human lung microvascular endothelial cells. Hsp90 inhibitors stabilize the Sirt-2/promoter interaction and impose a "transcriptional block," which is reversed by either inhibition or downregulation of Sirt-2 protein expression. Furthermore, this process is independent of NF-κB (p65) Lysine 310 deacetylation, suggesting that it is distinct from known Sirt-2-dependent mechanisms. We demonstrate that Sirt-2 is recruited to NF-κB target gene promoter via interaction with core histones. Upon inflammatory challenge, chromatin remodeling and core histone H3 displacement from the promoter region removes Sirt-2 and allows NF-κB/coactivator recruitment essential for RNA Pol II-dependent mRNA induction. This novel mechanism may have important implications in pulmonary inflammation.

  19. Interaction with specific HSP90 residues as a scoring function: validation in the D3R Grand Challenge 2015

    Science.gov (United States)

    Santos-Martins, Diogo

    2016-09-01

    Here is reported the development of a novel scoring function that performs remarkably well at identifying the native binding pose of a subset of HSP90 inhibitors containing aminopyrimidine or resorcinol based scaffolds. This scoring function is called PocketScore, and consists of the interaction energy between a ligand and three residues in the binding pocket: Asp93, Thr184 and a water molecule. We integrated PocketScore into a molecular docking workflow, and used it to participate in the Drug Design Data Resource (D3R) Grand Challenge 2015 (GC2015). PocketScore was able to rank 180 molecules of the GC2015 according to their binding affinity with satisfactory performance. These results indicate that the specific residues considered by PocketScore are determinant to properly model the interaction between HSP90 and its subset of inhibitors containing aminopyrimidine or resorcinol based scaffolds. Moreover, the development of PocketScore aimed at improving docking power while neglecting the prediction of binding affinities, suggesting that accurate identification of native binding poses is a determinant factor for the performance of virtual screens.

  20. HSP90 Regulation of P2X7 Receptor Function Requires an Intact Cytoplasmic C-Terminus.

    Science.gov (United States)

    Migita, Keisuke; Ozaki, Taku; Shimoyama, Shuji; Yamada, Junko; Nikaido, Yoshikazu; Furukawa, Tomonori; Shiba, Yuko; Egan, Terrance M; Ueno, Shinya

    2016-08-01

    P2X7 receptors (P2X7Rs) are ATP-gated ion channels that display the unusual property of current facilitation during long applications of agonists. Here we show that facilitation disappears in chimeric P2X7Rs containing the C-terminus of the P2X2 receptor (P2X2R), and in a truncated P2X7R missing the cysteine-rich domain of the C-terminus. The chimeric and truncated receptors also show an apparent decreased permeability to N-methyl-d-glucamine(+) (NMDG(+)). The effects of genetic modification of the C-terminus on NMDG(+) permeability were mimicked by preapplication of the HSP90 antagonist geldanamycin to the wild-type receptor. Further, the geldanamycin decreased the shift in the reversal potential of the ATP-gated current measured under bi-ionic NMDG(+)/Na(+) condition without affecting the ability of the long application of agonist to facilitate current amplitude. Taken together, the results suggest that HSP90 may be essential for stabilization and function of P2X7Rs through an action on the cysteine-rich domain of the cytoplasmic the C-terminus.

  1. Low sequence identity but high structural and functional conservation: The case of Hsp70/Hsp90 organizing protein (Hop/Sti1) of Leishmania braziliensis.

    Science.gov (United States)

    Batista, Fernanda A H; Seraphim, Thiago V; Santos, Clelton A; Gonzaga, Marisvanda R; Barbosa, Leandro R S; Ramos, Carlos H I; Borges, Júlio C

    2016-06-15

    Parasites belonging to the genus Leishmania are subjected to extensive environmental changes during their life cycle; molecular chaperones/co-chaperones act as protagonists in this scenario to maintain cellular homeostasis. Hop/Sti1 is a co-chaperone that connects the Hsp90 and Hsp70 systems, modulating their ATPase activities and affecting the fate of client proteins because it facilitates their transfer from the Hsp70 to the Hsp90 chaperone. Hop/Sti1 is one of the most prevalent co-chaperones, highlighting its importance despite the relatively low sequence identity among orthologue proteins. This multi-domain protein comprises three tetratricopeptides domains (TPR1, TPR2A and TPR2B) and two Asp/Pro-rich domains. Given the importance of Hop/Sti1 for the chaperone system and for Leishmania protozoa viability, the Leishmania braziliensis Hop (LbHop) and a truncated mutant (LbHop(TPR2AB)) were characterized. Structurally, both proteins are α-helix-rich and highly elongated monomeric proteins. Functionally, they inhibited the ATPase activity of Leishmania braziliensis Hsp90 (LbHsp90) to a similar extent, and the thermodynamic parameters of their interactions with LbHsp90 were similar, indicating that TPR2A-TPR2B forms the functional center for the LbHop interaction with LbHsp90. These results highlight the structural and functional similarity of Hop/Sti1 proteins, despite their low sequence conservation compared to the Hsp70 and Hsp90 systems, which are phylogenetic highly conserved.

  2. [The Role of Membrane-Bound Heat Shock Proteins Hsp90 in Migration of Tumor Cells in vitro and Involvement of Cell Surface Heparan Sulfate Proteoglycans in Protein Binding to Plasma Membrane].

    Science.gov (United States)

    Snigireva, A V; Vrublevskaya, V V; Skarga, Y Y; Morenkov, O S

    2016-01-01

    Heat shock protein Hsp90, detected in the extracellular space and on the membrane of cells, plays an important role in cell motility, migration, invasion and metastasis of tumor cells. At present, the functional role and molecular mechanisms of Hsp90 binding to plasma membrane are not elucidated. Using isoform-specific antibodies against Hsp90, Hsp9α and Hsp90β, we showed that membrane-bound Hsp90α and Hsp90β play a significant role in migration of human fibrosarcoma (HT1080) and glioblastoma (A-172) cells in vitro. Disorders of sulfonation of cell heparan sulfates, cleavage of cell heparan. sulfates by heparinase I/III as well as treatment of cells with heparin lead to an abrupt reduction in the expression level of Hsp90 isoforms. Furthermore, heparin significantly inhibits tumor cell migration. The results obtained demonstrate that two isoforms of membrane-bound Hsp90 are involved in migration of tumor cells in vitro and that cell surface heparan sulfate proteoglycans play a pivotal role in the "anchoring" of Hsp90α and Hsp90β to the plasma membrane.

  3. 2.4 Å resolution crystal structure of human TRAP1NM, the Hsp90 paralog in the mitochondrial matrix.

    Science.gov (United States)

    Sung, Nuri; Lee, Jungsoon; Kim, Ji Hyun; Chang, Changsoo; Tsai, Francis T F; Lee, Sukyeong

    2016-08-01

    TRAP1 is an organelle-specific Hsp90 paralog that is essential for neoplastic growth. As a member of the Hsp90 family, TRAP1 is presumed to be a general chaperone facilitating the late-stage folding of Hsp90 client proteins in the mitochondrial matrix. Interestingly, TRAP1 cannot replace cytosolic Hsp90 in protein folding, and none of the known Hsp90 co-chaperones are found in mitochondria. Thus, the three-dimensional structure of TRAP1 must feature regulatory elements that are essential to the ATPase activity and chaperone function of TRAP1. Here, the crystal structure of a human TRAP1NM dimer is presented, featuring an intact N-domain and M-domain structure, bound to adenosine 5'-β,γ-imidotriphosphate (ADPNP). The crystal structure together with epitope-mapping results shows that the TRAP1 M-domain loop 1 contacts the neighboring subunit and forms a previously unobserved third dimer interface that mediates the specific interaction with mitochondrial Hsp70.

  4. 2.4 Å resolution crystal structure of human TRAP1 NM , the Hsp90 paralog in the mitochondrial matrix

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Nuri; Lee, Jungsoon; Kim, Ji-Hyun; Chang, Changsoo; Tsai, Francis T. F.; Lee, Sukyeong

    2016-07-13

    TRAP1 is an organelle-specific Hsp90 paralog that is essential for neoplastic growth. As a member of the Hsp90 family, TRAP1 is presumed to be a general chaperone facilitating the late-stage folding of Hsp90 client proteins in the mitochondrial matrix. Interestingly, TRAP1 cannot replace cytosolic Hsp90 in protein folding, and none of the known Hsp90 co-chaperones are found in mitochondria. Thus, the three-dimensional structure of TRAP1 must feature regulatory elements that are essential to the ATPase activity and chaperone function of TRAP1. Here, the crystal structure of a human TRAP1NMdimer is presented, featuring an intact N-domain and M-domain structure, bound to adenosine 5'-β,γ-imidotriphosphate (ADPNP). The crystal structure together with epitope-mapping results shows that the TRAP1 M-domain loop 1 contacts the neighboring subunit and forms a previously unobserved third dimer interface that mediates the specific interaction with mitochondrial Hsp70.

  5. Integration of gene dosage and gene expression in non-small cell lung cancer, identification of HSP90 as potential target.

    Directory of Open Access Journals (Sweden)

    Mariëlle I Gallegos Ruiz

    Full Text Available BACKGROUND: Lung cancer causes approximately 1.2 million deaths per year worldwide, and non-small cell lung cancer (NSCLC represents 85% of all lung cancers. Understanding the molecular events in non-small cell lung cancer (NSCLC is essential to improve early diagnosis and treatment for this disease. METHODOLOGY AND PRINCIPAL FINDINGS: In an attempt to identify novel NSCLC related genes, we performed a genome-wide screening of chromosomal copy number changes affecting gene expression using microarray based comparative genomic hybridization and gene expression arrays on 32 radically resected tumor samples from stage I and II NSCLC patients. An integrative analysis tool was applied to determine whether chromosomal copy number affects gene expression. We identified a deletion on 14q32.2-33 as a common alteration in NSCLC (44%, which significantly influenced gene expression for HSP90, residing on 14q32. This deletion was correlated with better overall survival (P = 0.008, survival was also longer in patients whose tumors had low expression levels of HSP90. We extended the analysis to three independent validation sets of NSCLC patients, and confirmed low HSP90 expression to be related with longer overall survival (P = 0.003, P = 0.07 and P = 0.04. Furthermore, in vitro treatment with an HSP90 inhibitor had potent antiproliferative activity in NSCLC cell lines. CONCLUSIONS: We suggest that targeting HSP90 will have clinical impact for NSCLC patients.

  6. 2,4-dihydroxy benzaldehyde derived Schiff bases as small molecule Hsp90 inhibitors: rational identification of a new anticancer lead.

    Science.gov (United States)

    Dutta Gupta, Sayan; Revathi, B; Mazaira, Gisela I; Galigniana, Mario D; Subrahmanyam, C V S; Gowrishankar, N L; Raghavendra, N M

    2015-04-01

    Hsp90 is a molecular chaperone that heals diverse array of biomolecules ranging from multiple oncogenic proteins to the ones responsible for development of resistance to chemotherapeutic agents. Moreover they are over-expressed in cancer cells as a complex with co-chaperones and under-expressed in normal cells as a single free entity. Hence inhibitors of Hsp90 will be more effective and selective in destroying cancer cells with minimum chances of acquiring resistance to them. In continuation of our goal to rationally develop effective small molecule azomethines against Hsp90, we designed few more compounds belonging to the class of 2,4-dihydroxy benzaldehyde derived imines (1-13) with our validated docking protocol. The molecules exhibiting good docking score were synthesized and their structures were confirmed by IR, (1)H NMR and mass spectral analysis. Subsequently, they were evaluated for their potential to suppress Hsp90 ATPase activity by Malachite green assay. The antiproliferative effect of the molecules were examined on PC3 prostate cancer cell lines by adopting 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay methodology. Finally, schiff base 13 emerged as the lead molecule for future design and development of Hsp90 inhibitors as anticancer agents.

  7. Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

    Directory of Open Access Journals (Sweden)

    Jonathan E Nuss

    Full Text Available Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV. Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90, as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

  8. Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

    Science.gov (United States)

    Nuss, Jonathan E; Kehn-Hall, Kylene; Benedict, Ashwini; Costantino, Julie; Ward, Michael; Peyser, Brian D; Retterer, Cary J; Tressler, Lyal E; Wanner, Laura M; McGovern, Hugh F; Zaidi, Anum; Anthony, Scott M; Kota, Krishna P; Bavari, Sina; Hakami, Ramin M

    2014-01-01

    Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

  9. The targeted inhibition of mitochondrial Hsp90 overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Chunlan [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Oh, Joon Seok; Yoo, Seung Hee; Lee, Jee Suk [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoon, Young Geol [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Biomedical Science, Institute for Biomedical and Health Sciences, Jungwon University, Chungbuk, 367-805 (Korea, Republic of); Oh, Yoo Jin; Jang, Min Seok [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Lee, Sang Yeob [Department of Rheumatology, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Yang, Jun [Department of Toxicology, Hangzhou Normal University School of Public Health, Hangzhou, Zhejiang, 310036 China (China); Lee, Sang Hwa [Department of Microbiology and, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Kim, Hye Young [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoo, Young Hyun, E-mail: yhyoo@dau.ac.kr [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of)

    2013-01-01

    Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantly inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis. Highlights: ► G-TPP binds to mitochondrial Hsp90. ► G-TPP induces apoptosis in U937 human leukemia cancer cells. ► G-TPP induces combination of death pathways in Hep3B cell. ► G-TPP overcomes the resistance conferred by Bcl-2 in Hep3B cells via necroptosis. ► G-TPP triggers Beclin 1-independent

  10. MicroRNA-27b plays a role in pulmonary arterial hypertension by modulating peroxisome proliferator-activated receptor γ dependent Hsp90-eNOS signaling and nitric oxide production

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Rui; Bao, Chunrong; Jiang, Lianyong; Liu, Hao; Yang, Yang; Mei, Ju; Ding, Fangbao, E-mail: dbcar126@126.com

    2015-05-01

    Pulmonary artery endothelial dysfunction is associated with pulmonary arterial hypertension (PAH). Based on recent studies showing that microRNA (miR)-27b is aberrantly expressed in PAH, we hypothesized that miR-27b may contribute to pulmonary endothelial dysfunction and vascular remodeling in PAH. The effect of miR-27b on pulmonary endothelial dysfunction and the underlying mechanism were investigated in human pulmonary artery endothelial cells (HPAECs) in vitro and in a monocrotaline (MCT)-induced model of PAH in vivo. miR-27b expression was upregulated in MCT-induced PAH and inversely correlated with the levels of peroxisome proliferator-activated receptor (PPAR)-γ, and miR-27b inhibition attenuated MCT-induced endothelial dysfunction and remodeling and prevented PAH associated right ventricular hypertrophy and systolic pressure in rats. PPARγ was confirmed as a direct target of miR-27b in HPAECs and shown to mediate the effect of miR-27b on the disruption of endothelial nitric oxide synthase (eNOS) coupling to Hsp90 and the suppression of NO production associated with the PAH phenotype. We showed that miR-27b plays a role endothelial function and NO release and elucidated a potential mechanism by which miR-27b regulates Hsp90-eNOS and NO signaling by modulating PPARγ expression, providing potential therapeutic targets for the treatment of PAH. - Highlights: • miR-27b plays a role in endothelial function and NO release. • miR-27b inhibition ameliorates MCT-induced endothelial dysfunction and PAH. • miR-27b targets PPARγ in HPAECs. • miR-27b regulates PPARγ dependent Hsp90-eNOS and NO signaling.

  11. A Homogeneous Polysaccharide from Fructus Schisandra chinensis (Turz. Baill Induces Mitochondrial Apoptosis through the Hsp90/AKT Signalling Pathway in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Yonglin Chen

    2016-06-01

    Full Text Available According to the potential anti-hepatoma therapeutic effect of Schisandra chinensis polysaccharides presented in previous studies, a bioactive constituent, homogeneous Schisandra chinensis polysaccharide-0-1 (SCP-0-1, molecular weight (MW circa 69.980 kDa, was isolated and purified. We assessed the efficacy of SCP-0-1 against human hepatocellular liver carcinoma (HepG2 cells to investigate the effects of its antitumour activity and molecular mechanisms. Anticancer activity was evaluated using microscopy, 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyltetrazolium bromide (MTT assay, Hoechst 33258 staining, acridine orange (AO staining, flow cytometry (FCM, and cell-cycle analysis. SCP-0-1 inhibited the HepG2 cells’ growth via inducing apoptosis and second gap/mitosis (G2/M arrest dose-dependently, with a half maximal inhibitory concentration (IC50 value of 479.63 µg/mL. Western blotting of key proteins revealed the apoptotic and autophagic potential of SCP-0-1. Besides, SCP-0-1 upregulated Bcl-2 Associated X Protein (Bax and downregulated B-cell leukemia/lymphoma 2 (Bcl-2 in the HepG2 cells. The expression of caspase-3, -8, and -9; poly (ADP-ribose polymerase (PARP; cytochrome c (Cyt C; tumor protein 53 (p53; survivin; sequestosome 1 (p62; microtubule-associated protein 1 light chain-3B (LC3B; mitogen-activated protein kinase p38 (p38; extracellular regulated protein kinases (ERK; c-Jun N-terminal kinase (JNK; protein kinase B (AKT; and heat shock protein 90 (Hsp90 were evaluated using Western blotting. Our findings demonstrate a novel mechanism through which SCP-0-1 exerts its antiproliferative activity and induces mitochondrial apoptosis rather than autophagy. The induction of mitochondrial apoptosis was attributed to the inhibition of the Hsp90/AKT signalling pathway in an extracellular signal-regulated kinase-independent manner. The results also provide initial evidence on a molecular basis that SCP-0-1 can be used as an anti

  12. A Homogeneous Polysaccharide from Fructus Schisandra chinensis (Turz.) Baill Induces Mitochondrial Apoptosis through the Hsp90/AKT Signalling Pathway in HepG2 Cells

    Science.gov (United States)

    Chen, Yonglin; Shi, Songshan; Wang, Huijun; Li, Ning; Su, Juan; Chou, Guixin; Wang, Shunchun

    2016-01-01

    According to the potential anti-hepatoma therapeutic effect of Schisandra chinensis polysaccharides presented in previous studies, a bioactive constituent, homogeneous Schisandra chinensis polysaccharide-0-1 (SCP-0-1), molecular weight (MW) circa 69.980 kDa, was isolated and purified. We assessed the efficacy of SCP-0-1 against human hepatocellular liver carcinoma (HepG2) cells to investigate the effects of its antitumour activity and molecular mechanisms. Anticancer activity was evaluated using microscopy, 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33258 staining, acridine orange (AO) staining, flow cytometry (FCM), and cell-cycle analysis. SCP-0-1 inhibited the HepG2 cells’ growth via inducing apoptosis and second gap/mitosis (G2/M) arrest dose-dependently, with a half maximal inhibitory concentration (IC50) value of 479.63 µg/mL. Western blotting of key proteins revealed the apoptotic and autophagic potential of SCP-0-1. Besides, SCP-0-1 upregulated Bcl-2 Associated X Protein (Bax) and downregulated B-cell leukemia/lymphoma 2 (Bcl-2) in the HepG2 cells. The expression of caspase-3, -8, and -9; poly (ADP-ribose) polymerase (PARP); cytochrome c (Cyt C); tumor protein 53 (p53); survivin; sequestosome 1 (p62); microtubule-associated protein 1 light chain-3B (LC3B); mitogen-activated protein kinase p38 (p38); extracellular regulated protein kinases (ERK); c-Jun N-terminal kinase (JNK); protein kinase B (AKT); and heat shock protein 90 (Hsp90) were evaluated using Western blotting. Our findings demonstrate a novel mechanism through which SCP-0-1 exerts its antiproliferative activity and induces mitochondrial apoptosis rather than autophagy. The induction of mitochondrial apoptosis was attributed to the inhibition of the Hsp90/AKT signalling pathway in an extracellular signal-regulated kinase-independent manner. The results also provide initial evidence on a molecular basis that SCP-0-1 can be used as an anti

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

    Science.gov (United States)

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

    2014-10-17

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

  14. Expression of RPS4 in tobacco induces an AvrRps4-independent HR that requires EDS1, SGT1 and HSP90.

    Science.gov (United States)

    Zhang, Yan; Dorey, Stephan; Swiderski, Michal; Jones, Jonathan D G

    2004-10-01

    The Arabidopsis RPS4 gene belongs to the Toll/interleukin-1 receptor/nucleotide-binding site/leucine-rich repeat (TIR-NB-LRR) class of plant resistance (R) genes. It confers resistance to Pseudomonas syringae carrying the avirulence gene avrRps4. Transient expression of genomic RPS4 driven by the 35S promoter in tobacco leaves induces an AvrRps4-independent hypersensitive response (HR). The same phenotype is seen after expression of a full-length RPS4 cDNA. This indicates that alternative splicing of RPS4 is not involved in this HR. The extent of HR is correlated with RPS4 protein levels. Deletion analyses of RPS4 domains show the TIR domain is required for the HR phenotype. Mutations in the P-loop motif of the NB domain abolish the HR. Using virus-induced gene silencing, we found that the cell death resulting from RPS4 expression is dependent on the three plant signalling components EDS1, SGT1 and HSP90. All these data suggest that heterologous expression of an R gene can result in activation of cell death even in the absence of its cognate avirulence product, and provides a system for studying the RPS4 domains required for HR.

  15. 2-phenylethynesulphonamide (PFT-μ) enhances the anticancer effect of the novel hsp90 inhibitor NVP-AUY922 in melanoma, by reducing GSH levels.

    Science.gov (United States)

    Yeramian, Andree; Vea, Alvar; Benítez, Sandra; Ribera, Joan; Domingo, Mónica; Santacana, Maria; Martinez, Montserrat; Maiques, Oscar; Valls, Joan; Dolcet, Xavier; Vilella, Ramón; Cabiscol, Elisa; Matias-Guiu, Xavier; Marti, Rosa M

    2016-05-01

    Heat shock proteins (HSPs), are molecular chaperones that assist the proper folding of nascent proteins. This study aims to evaluate the antitumour effects of the hsp90 inhibitor NVP-AUY922 in melanoma, both in vitro and in vivo. Our results show that NVP-AUY922 inhibits melanoma cell growth in vitro, with down regulation of multiple signalling pathways involved in melanoma progression such as NF-ĸB and MAPK/ERK. However, NVP-AUY922 was unable to limit tumour growth in vivo. Cotreatment of A375M xenografts with NVP-AUY922 and PFT-μ, a dual inhibitor of both hsp70 and autophagy, induced a synergistic increase of cell death in vitro, and delayed tumour formation in A375M xenografts. PFT-μ depleted cells from the reduced form of glutathione (GSH) and increased oxidative stress. The oxidative stress induced by PFT-μ further enhanced NVP-AUY922-induced cytotoxic effects. These data suggest a potential therapeutic role for NVP-AUY922 used in combination with PFT-μ, in melanoma.

  16. Enhanced in vivo antitumor efficacy of dual-functional peptide-modified docetaxel nanoparticles through tumor targeting and Hsp90 inhibition.

    Science.gov (United States)

    Jiang, Yao; Yang, Nan; Zhang, Huifeng; Sun, Bo; Hou, Chunying; Ji, Chao; Zheng, Ji; Liu, Yanyong; Zuo, Pingping

    2016-01-10

    Although conventional anticancer drugs exhibit excellent efficacy, serious adverse effects and/or even toxicity have occurred due to their nonselectivity. Moreover, active targeting approaches have not consistently led to successful outcomes. Ligands that simultaneously possess targeting capability and exert a strong influence on intracellular signaling cascades may be expected to improve the therapeutic efficacy of active targeting nanoparticulate carriers. In this study, we screened a targeting peptide, LPLTPLP, which specifically bound to non-small cell lung cancer (NSCLC) specimens in vitro. Surprisingly, this peptide inhibited the expression of Hsp90 and induced apoptosis by preventing autophagy in A549 cells treated with docetaxel. The results suggested that this peptide might be used as a promising dual-functional ligand for cancer treatment. Based on these findings, we designed and developed a novel active targeting delivery system by modifying docetaxel nanoparticles (DNP) with the dual-functional ligand LPLTPLP. We consistently demonstrated that the cellular uptake of nanoparticles (NPs) was significantly enhanced in vitro. Furthermore, the targeting NPs exhibited significantly improved antitumor efficacy and biodistribution compared with nontargeting nanodrug and free docetaxel. These findings demonstrate the feasibility of dual-functional NPs for efficient anticancer therapy.

  17. Heat shock protein genes (hsp20, hsp75 and hsp90) from Pieris rapae: Molecular cloning and transcription in response to parasitization by Pteromalus puparum

    Institute of Scientific and Technical Information of China (English)

    Jia-Ying Zhu; Guo-Xing Wu; Gong-Yin Ye; Cui Hu

    2013-01-01

    Most molecular work on the roles of heat shock proteins (hsps) in host-parasite interaction has focused on vertebrates,rather than invertebrates.Here the full length complementary DNA (cDNA) sequences of three hsp genes (hsp20,hsp75 and hsp90)were amplified from Pieris rapae,and their transcriptional responsiveness to parasitization by the endoparasitic wasp Pteromalus puparum were investigated.The cDNA sequence analysis of hsp20,hsp75 and hsp90 revealed open reading frames of 531,2 328 and 2 157 bp in length,which encode proteins with calculated molecular weights of 19.5,75.48 and 82.7 kDa,respectively.The comparison of amino acid sequences showed that P.rapae hsp20 shared highly divergent homology to that of other insects,while hsp75 and hsp90 showed high homology to their counterparts of other species.The expression analysis indicated that these three genes were influenced in response to parasitization by P.puparum.The hsp20 transcripts in parasitized pupae were higher compared to nonparasitized pupae.The expression of hsp75 and hsp90 were down-regulated following parasitization.The results indicate that hsps are involved in host-parasitoid interactions.

  18. Hsp90 regulates processing of NF-κB2 p100 involving protection of NF-κB-inducing kinase (NIK) from autophagy-mediated degradation

    Institute of Scientific and Technical Information of China (English)

    Guoliang Qing; Pengrong Yan; Zhaoxia Qu; Hudan Liu; Gutian Xiao

    2007-01-01

    NF-κB-inducing kinase (NIK) is required for NF-κB activation based on the processing of NF-κB2 p100. Here we report a novel mechanism of NIK regulation involving the chaperone 90 kDa heat shock protein (Hsp90) and autophagy.Functional inhibition of lisp90 by the anti-tumor agent geldanamycin (GA) efficiently disrupts its interaction with NIK,resulting in NIK degradation and subsequent blockage of p100 processing. Surprisingly, GA-induced NIK degradation is mediated by autophagy, but largely independent of the ubiquitin-proteasome system. Hsp90 seems to be specifically involved in the folding/stabilization of NIK protein, because GA inhibition does not affect NIK mRNA transcription and translation. Furthermore, Hsp90 is not required for NIK-mediated recruitment of the α subunit of IκB kinase to p100, a key step in induction of p100 processing. These findings define an alternative mechanism for Hsp90 client degradation and identify a novel function of autophagy in NF-κB regulation. These findings also suggest a new therapeutic strategy for diseases associated with p100 processing.

  19. Acidosis Acts through HSP90 in a PHD/VHL-Independent Manner to Promote HIF Function and Stem Cell Maintenance in Glioma.

    Science.gov (United States)

    Filatova, Alina; Seidel, Sascha; Böğürcü, Nuray; Gräf, Sabine; Garvalov, Boyan K; Acker, Till

    2016-10-01

    Hypoxia is a common feature of solid tumors, which controls multiple aspects of cancer progression. One important function of hypoxia and the hypoxia-inducible factors (HIF) is the maintenance of cancer stem-like cells (CSC), a population of tumor cells that possess stem cell-like properties and drives tumor growth. Among the changes promoted by hypoxia is a metabolic shift resulting in acidification of the tumor microenvironment. Here, we show that glioma hypoxia and acidosis functionally cooperate in inducing HIF transcription factors and CSC maintenance. We found that these effects did not involve the classical PHD/VHL pathway for HIF upregulation, but instead involved the stress-induced chaperone protein HSP90. Genetic or pharmacologic inactivation of HSP90 inhibited the increase in HIF levels and abolished the self-renewal and tumorigenic properties of CSCs induced by acidosis. In clinical specimens of glioma, HSP90 was upregulated in the hypoxic niche and was correlated with a CSC phenotype. Our findings highlight the role of tumor acidification within the hypoxic niche in the regulation of HIF and CSC function through HSP90, with implications for therapeutic strategies to target CSC in gliomas and other hypoxic tumors. Cancer Res; 76(19); 5845-56. ©2016 AACR.

  20. Chromosomal assignment of six genes (EIF4G3, HSP90, RBBP6, IL8, TERT, and TERC) in four species of the genus Equus.

    Science.gov (United States)

    Vidale, Pamela; Piras, Francesca M; Nergadze, Solomon G; Bertoni, Livia; Verini-Supplizi, Andrea; Adelson, David; Guérin, Gérard; Giulotto, Elena

    2011-01-01

    We mapped six genes (EIF4G3, HSP90, RBBP6, IL8, TERT, and TERC) on the chromosomes of Equus caballus, Equus asinus, Equus grevyi, and Equus burchelli by fluorescence in situ hybridization. Our results add six type I markers to the cytogenetic map of these species and provide new information on the comparative genomics of the genus Equus.

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

    Science.gov (United States)

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

    2014-05-01

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

  2. The myosin-binding UCS domain but not the Hsp90-binding TPR domain of the UNC-45 chaperone is essential for function in Caenorhabditis elegans.

    Science.gov (United States)

    Ni, Weiming; Hutagalung, Alex H; Li, Shumin; Epstein, Henry F

    2011-09-15

    The UNC-45 family of molecular chaperones is expressed in metazoan organisms from Caenorhabditis elegans to humans. The UNC-45 protein is essential in C. elegans for early body-wall muscle cell development and A-band assembly. We show that the myosin-binding UCS domain of UNC-45 alone is sufficient to rescue lethal unc-45 null mutants arrested in embryonic muscle development and temperature-sensitive loss-of-function unc-45 mutants defective in worm A-band assembly. Removal of the Hsp90-binding TPR domain of UNC-45 does not affect rescue. Similar results were obtained with overexpression of the same fragments in wild-type nematodes when assayed for diminution of myosin accumulation and assembly. Titration experiments show that, on a per molecule basis, UCS has greater activity in C. elegans muscle in vivo than full-length UNC-45 protein, suggesting that UNC-45 is inhibited by either the TPR domain or its interaction with the general chaperone Hsp90. In vitro experiments with purified recombinant C. elegans Hsp90 and UNC-45 proteins show that they compete for binding to C. elegans myosin. Our in vivo genetic and in vitro biochemical experiments are consistent with a novel inhibitory role for Hsp90 with respect to UNC-45 action.

  3. Dexamethasone regulates CFTR expression in Calu-3 cells with the involvement of chaperones HSP70 and HSP90.

    Directory of Open Access Journals (Sweden)

    Luiz Felipe M Prota

    Full Text Available BACKGROUND: Dexamethasone is widely used for pulmonary exacerbation in patients with cystic fibrosis, however, not much is known about the effects of glucocorticoids on the wild-type cystic fibrosis channel transmembrane regulator (CFTR. Our aim was to determine the effects of dexamethasone treatment on wild-type CFTR expression. METHODS AND RESULTS: Dose-response (1 nM to 10 µM and time course (3 to 48 h curves were generated for dexamethasone for mRNA expression in Calu-3 cells using a real-time PCR. Within 24 h, dexamethasone (10 nM showed a 0.3-fold decrease in CFTR mRNA expression, and a 3.2-fold increase in αENaC mRNA expression compared with control groups. Dexamethasone (10 nM induced a 1.97-fold increase in the total protein of wild-type CFTR, confirmed by inhibition by mifepristone. To access surface protein expression, biotinylation followed by Western blotting showed that dexamethasone treatment led to a 2.35-fold increase in the amount of CFTR in the cell surface compared with the untreated control groups. Once protein translation was inhibited with cycloheximide, dexamethasone could not increase the amount of CFTR protein. Protein stability was assessed by inhibition of protein synthesis with cycloheximide (50 µg/ml at different times in cells treated with dexamethasone and in untreated cells. Dexamethasone did not alter the degradation of wild-type CFTR. Assessment of the B band of CFTR within 15 min of metabolic pulse labeling showed a 1.5-fold increase in CFTR protein after treatment with dexamethasone for 24 h. Chaperone 90 (HSP90 binding to CFTR increased 1.55-fold after treatment with dexamethasone for 24 h, whereas chaperone 70 (HSP70 binding decreased 0.30 fold in an immunoprecipitation assay. CONCLUSION: Mature wild-type CFTR protein is regulated by dexamethasone post transcription, involving cotranslational mechanisms with HSP90 and HSP70, which enhances maturation and expression of wild-type CFTR.

  4. Mactinin, a fragment of cytoskeletal α-actinin, is a novel inducer of heat shock protein (Hsp-90 mediated monocyte activation

    Directory of Open Access Journals (Sweden)

    Perri Robert T

    2009-08-01

    Full Text Available Abstract Background Monocytes, their progeny such as dendritic cells and osteoclasts and products including tumor necrosis factor (TNF-α, interleukin (IL-1α and IL-1β play important roles in cancer, inflammation, immune response and atherosclerosis. We previously showed that mactinin, a degradative fragment of the cytoskeletal protein α-actinin, is present at sites of monocytic activation in vivo, has chemotactic activity for monocytes and promotes monocyte/macrophage maturation. We therefore sought to determine the mechanism by which mactinin stimulates monocytes. Results Radiolabeled mactinin bound to a heterocomplex on monocytes comprised of at least 3 proteins of molecular weight 88 kD, 79 kD and 68 kD. Affinity purification, mass spectroscopy and Western immunoblotting identified heat shock protein (Hsp-90 as the 88 kD component of this complex. Hsp90 was responsible for mediating the functional effects of mactinin on monocytes, since Hsp90 inhibitors (geldanamycin and its analogues 17-allylamino-17-demethoxygeldanamycin [17-AAG] and 17-(dimethylaminoethylamino-17-demethoxygeldanamycin [17-DMAG] almost completely abrogated the stimulatory activity of mactinin on monocytes (production of the pro-inflammatory cytokines IL-1α, IL-1β and TNF-α, as well as monocyte chemotaxis. Conclusion Mactinin is a novel inducer of Hsp90 activity on monocytes and may serve to perpetuate and augment monocytic activation, thereby functioning as a "matrikine." Blockage of this function of mactinin may be useful in diseases where monocyte/macrophage activation and/or Hsp90 activity are detrimental.

  5. Development and application of fluorescence polarization assay for high throughput screening of geldanamycin-Hsp90α binding%荧光偏振法建立格尔德霉素-Hsp90α结合高通量筛选模型及其应用

    Institute of Scientific and Technical Information of China (English)

    董飚; 陶佩珍; 李艳萍; 李玉环

    2011-01-01

    Objective:To establish a high throughput screening, fluorescence polarization assay of binding between Hsp90α and geldanamycin, to identify novel geldanamycin derivatives. Methods: The assay was based on the fluorescence polarization theory by using fluorescein isothiocyanate (FITC) labeled geldanamycin (GA) for binding to Hsp90α in homogeneous solution. Affinity of novel geldanamycin derivatives for Hsp90α was measured by competitive assay. Results:The fluorescence polarization assay for Hsp90 using a fluorescent GA ligand was successfully established, of which Z factor value reached 0. 641. Among the measured geldanamycin derivative samples, GA-APML and GA-AEPD caused inhibition effects on the binding of GA-Hsp90α with IC50 of 82.98 and 90. 06 nmol·L-1, respectively. Conclusion: The fluorescence polarization assay for GA-Hsp binding basically meets the standard required by high throughput screening experiments. The designed geldanamycin derivatives still have same affinity to Hsp90α as the geldanamycin itself, which shows it is feasible to modify the structure of geldanamycin at these sites.%目的:建立格尔德霉素(geldanamycin,GA)-Hsp90α结合高通量荧光偏振法筛选模型及应用此模型探查新的格尔德霉素衍生物.方法:本模型利用荧光偏振原理,在均相溶液中,以异硫氰酸荧光素(FITC)标记的格尔德霉素作为配基,与Hsp90α蛋白作用,采用荧光仪检测荧光偏振值.以竞争性结合方式评价新格尔德霉素衍生物对Hsp90α的亲和力,以期找出更好的格尔德霉素衍生物.结果:成功建立了荧光偏振原理的格尔德霉素-Hsp90α结合模型,其Z因子可达0.641.所测试的格尔德霉素衍生物样品中,GA-APML和GA-AEPD抑制GA-Hsp90α结合的IC50分别为82.98和90.06 nmol·L-1.结论:建立的格尔德霉素-Hsp90α结合荧光偏振法模型基本达到进行高通量实验所需的标准.所设计格尔德霉素衍生物仍具备与格尔德霉素相同的对Hsp90

  6. Expression, purification and polyclonal antibody generation of p23,an Hsp90 cochaperone, in the amphioxus Branchiostoma belcheri

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bosheng; ZHANG Shicui; PANG Qiuxiang; LIU Zhenhui; LIANG Yujun

    2006-01-01

    The cDNA of amphioxus p23, a highly conserved co-chaperone for Hsp90, was cloned into a bacterial expression vector pGEX-6P-1 and the GST-tagged fusion protein was produced in Eschherichia coli cells. The recombinant p23 was purified by affinity purification, and its molecular mass was estimated to be approximately 22 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The N-terminus of purified p23 was sequenced, and the resulting amino acid sequence matches exactly the predicted residues deduced from the amphioxus p23 gene. Besides, polyclonal antibodies against the recombinant p23 were generated, and these antibodies not only recognized specifically the fusion protein GST-p23 from induced E. coli cells, purified GST-p23 and p23 protein, but also reacted with the total protein extracted from the adult amphioxus and formed a single positive band. These results pave the way for identifying its tissue and subcellular localization, and may open the door to clarifying its structure and mechanisms of biological role.

  7. The prokaryotic expression of recombinant heat shock protein HSP90a of Portunus trituberculatus under salinity stress%盐度胁迫下三疣梭子蟹热休克蛋白HSP90a的原核表达

    Institute of Scientific and Technical Information of China (English)

    覃烨; 许强华

    2012-01-01

    Heat shock protein 90 is a multi-functional molecular chaperone that plays an essential role in both cellular metabolism and stress response. The swimming crab, Portunus trituberculatus is an important marine fishery and aquaculture species. Water salinity conditions influence its artificial propagations significantly. In order to prove the relationships between HSP90a protein and salinity stress, we investigated the prokaryotic expression of P. trituberculatus HSP90a recombinant protein under a series of salinity stress. Based on the coding sequences of P. trituberculatus HSP90a protein in GenBank, we cloned the full length of HSP90a gene. Recombinant pET28-HSP90a prokaryotic expression recombinant plasmid was constructed and expressed in Escherichia coll DE3 (BL21) under a series of salinity stress. Results showed that the survival rate of recombinant plasmid transferred Escherichia coli was higher than that of empty vector transferred cells. When the salinity challenge was close to the salinity tolerance maximum value of E. coli, the difference of survival rate between those two kinds of cells became more significant. For example, at the highest salinity challenge condition (1 050 mmol/L), the survival rate of recombinant plasmid transferred E. coli was 10.7 times higher than that of empty vector transferred cells. Therefore, our results indicated that P. trituberculatus HSP90a protein possessed protective effect against salinity stress and HSP90a protein might be involved in salinity adaptation physiological process in P. trituberculatus.%为证明三疣梭子蟹HSP90a蛋白与盐度胁迫的相关性,实验根据GenBank上提供的三疣梭子蟹HSP90a基因蛋白编码区序列,构建pET28-HSP90a原核表达重组质粒在大肠杆菌DE3(BL21)中进行的盐度胁迫表达.结果显示,转重组质粒的大肠杆菌生存率明显高于转空载体的大肠杆菌,越接近大肠杆菌盐度耐受极限值,两者差异越显著,在盐度胁迫最高值(1 050

  8. A Cytosolic Relay of Heat Shock Proteins HSP70-1A and HSP90β Monitors the Folding Trajectory of the Serotonin Transporter*

    Science.gov (United States)

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

    2014-01-01

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase activity of purified HSP70-1A. (ii) A GST fusion protein comprising the C terminus of SERT pulled down HSP70-1A. The interaction between HSP70-1A and SERT was visualized in live cells by Förster resonance energy transfer: it was restricted to endoplasmic reticulum-resident transporters and enhanced by an inhibitor that traps HSP70-1A in its closed state. (iv) Co-immunoprecipitation confirmed complex formation of SERT with HSP70-1A and HSP90β. Consistent with an HSP relay, co-chaperones (e.g. HSC70-HSP90-organizing protein) were co-immunoprecipitated with the stalled mutants SERT-R607A/I608A and SERT-P601A/G602A. (v) Depletion of HSP90β by siRNA or its inhibition increased the cell surface expression of wild type SERT and SERT-F604Q. In contrast, SERT-R607A/I608A and SERT-P601A/G602A were only rendered susceptible to inhibition of HSP70 and HSP90 by concomitant pharmacochaperoning with noribogaine. (vi) In JAR cells, inhibition of HSP90 also increased the levels of SERT, indicating that endogenously expressed transporter was also susceptible to control by HSP90β. These findings support the concept that the folding trajectory of SERT is sampled by a cytoplasmic chaperone relay. PMID:25202009

  9. Hepatitis B virus polymerase suppresses NF-κB signaling by inhibiting the activity of IKKs via interaction with Hsp90β.

    Directory of Open Access Journals (Sweden)

    Dan Liu

    Full Text Available Nuclear factor-κB (NF-κB plays a central role in the regulation of diverse biological processes, including immune responses, development, cell growth, and cell survival. To establish persistent infection, many viruses have evolved strategies to evade the host's antiviral immune defenses. In the case of hepatitis B virus (HBV, which can cause chronic infection in the liver, immune evasion strategies used by the virus are not fully understood. It has recently been reported that the polymerase of HBV (Pol inhibits interferon-β (IFN-β activity by disrupting the interaction between IKKε and the DDX3. In the current study, we found that HBV Pol suppressed NF-κB signaling, which can also contribute to IFN-β production. HBV Pol did not alter the level of NF-κB expression, but it prevented NF-κB subunits involved in both the canonical and non-canonical NF-κB pathways from entering the nucleus. Further experiments demonstrated that HBV Pol preferentially suppressed the activity of the IκB kinase (IKK complex by disrupting the association of IKK/NEMO with Cdc37/Hsp90, which is critical for the assembly of the IKK complex and recruitment of the IKK complex to the tumor necrosis factor type 1 receptor (TNF-R1. Furthermore, we found that HBV Pol inhibited the NF-κB-mediated transcription of target genes. Taken together, it is suggested that HBV Pol could counteract host innate immune responses by interfering with two distinct signaling pathways required for IFN-β activation. Our studies therefore shed light on a potential therapeutic target for persistent infection with HBV.

  10. Repurposing L-Menthol for Systems Medicine and Cancer Therapeutics? L-Menthol Induces Apoptosis through Caspase 10 and by Suppressing HSP90.

    Science.gov (United States)

    Faridi, Uzma; Dhawan, Sunita S; Pal, Shaifali; Gupta, Sanchita; Shukla, Ashutosh K; Darokar, Mahendra P; Sharma, Ashok; Shasany, Ajit K

    2016-01-01

    The objective of the present study was to repurpose L-menthol, which is frequently used in oral health and topical formulations, for cancer therapeutics. In this article, we argue that monoterpenes such as L-menthol might offer veritable potentials in systems medicine, for example, as cheaper anti-cancer compounds. Other monoterpenes such as limonene, perillyl alcohol, and geraniol have been shown to induce apoptosis in various cancer cell lines, but their mechanisms of action are yet to be completely elucidated. Earlier, we showed that L-menthol modulates tubulin polymerization and apoptosis to inhibit cancer cell proliferation. In the present report, we used an apoptosis-related gene microarray in conjunction with proteomics analyses, as well as in silico interpretations, to study gene expression modulation in human adenocarcinoma Caco-2 cell line in response to L-menthol treatment. The microarray analysis identified caspase 10 as the important initiator caspase, instead of caspase 8. The proteomics analyses showed downregulation of HSP90 protein (also corroborated by its low transcript abundance), which in turn indicated inhibition of AKT-mediated survival pathway, release of pro-apoptotic factor BAD from BAD and BCLxL complex, besides regulation of other factors related to apoptosis. Based on the combined microarray, proteomics, and in silico data, a signaling pathway for L-menthol-induced apoptosis is being presented for the first time here. These data and literature analysis have significant implications for "repurposing" L-menthol beyond oral medicine, and in understanding the mode of action of plant-derived monoterpenes towards development of cheaper anticancer drugs in future.

  11. 5-Episinuleptolide Acetate, a Norcembranoidal Diterpene from the Formosan Soft Coral Sinularia sp., Induces Leukemia Cell Apoptosis through Hsp90 Inhibition

    Directory of Open Access Journals (Sweden)

    Yao-Tsung Yeh

    2013-03-01

    Full Text Available 5-Episinuleptolide acetate (5EPA, a cytotoxic norcembranoidal diterpene recently identified from the Formosan soft coral Sinularia sp., exhibited potent activity against the K562, Molt 4 and HL 60 cancer cell lines. The antiproliferative assay, as well as the annexin V-FITC/propidium iodide (PI apoptotic assay, indicated that the HL 60 cell line is the most sensitive one towards 5EPA. This diterpenoid led to caspases -3, -8, and -9 activation as well as PARP cleavage. It also induced ROS generation, calcium accumulation and disruption of mitochondrial membrane potential. Additionally, the expression levels of Hsp90 protein and several client proteins were downregulated in response to 5EPA treatment. These results suggest that 5EPA’s cytotoxic effect on HL 60 cells may be attributed to the inhibition of Hsp90 as well as the induction of mitochondrial stress which finally results in apoptotic cell death.

  12. Cloning and Sequence Analysis of Hsp90 and Hsp70 Gene from Carposina sasakii Matsumura under Heat Stress%高温胁迫下桃小食心虫热激蛋白Hsp90和Hsp70基因的克隆及序列分析

    Institute of Scientific and Technical Information of China (English)

    高萍; 贾向风; 王洪平

    2016-01-01

    桃小食心虫(Carposina sasakii Matsumura)是果树上重要的食心虫类害虫,热激蛋白Hsp90和Hsp70在昆虫抵御温度胁迫反应中具有重要作用。采用RT-PCR方法克隆获得了高温胁迫下桃小食心虫热激蛋白Hsp90和Hsp70基因cDNA部分序列,并对其进行分析,为深入揭示桃小食心虫对环境适应的分子机理提供理论依据。已获得的桃小食心虫热激蛋白Hsp90基因(GenBank登录号:KJ139642)序列长420bp,编码139个氨基酸残基,推导的氨基酸序列中含有热激蛋白90家族的一段序列为YSNKEIFLRE的特征序列,并且cDNA序列在N端具有Hsp90基因保守的ATPase结构,该序列与天蚕(Antheraea yamamai)和柞蚕(Antheraea pernyi)等昆虫的氨基酸序列一致性高达99%。已获得的Hsp70-1基因(GenBank登录号:KJ139643)和Hsp70-2基因(GenBank登录号:KJ139644)序列长均为305bp,编码101个氨基酸残基。 Hsp70-1基因推导的氨基酸序列与家蚕(Bombyx mori)的氨基酸序列一致性为94%,Hsp70-2基因推导的氨基酸序列与小菜蛾(Plutella xylostella)和烟草夜蛾(Manduca sexta)等昆虫的氨基酸序列一致性为96%。%Peach fruit moth,Carposina sasakii Matsumura is one of the main pests of the fruit trees. The heat shock protein 90 (Hsp90)and the heat shock protein70(Hsp70)widely exist in insects and play important role under temperature stress. In order to provide theoretical basis for exploring molecular mechanism of insect adaption to environment, partial-length cDNA encoding Hsp90 and Hsp70 from Carposina Sasakii were cloned by RT-PCR and the sequence was analyzed. Sequence analysis indicated that the partial cDNA of Hsp90 (GenBank accession number: KJ139642) was 420bp, encoding 139 amino acid residues. The deduced amino acid sequence contains an important Hsp90 family characteristic sequence(YSNKEIFLRE) and conservative ATPase structure in N-terminal domain, which shares 99% amino acid sequence identies with the Hsp90 genes from

  13. PKC signaling regulates drug resistance of the fungal pathogen Candida albicans via circuitry comprised of Mkc1, calcineurin, and Hsp90.

    Directory of Open Access Journals (Sweden)

    Shantelle L LaFayette

    Full Text Available Fungal pathogens exploit diverse mechanisms to survive exposure to antifungal drugs. This poses concern given the limited number of clinically useful antifungals and the growing population of immunocompromised individuals vulnerable to life-threatening fungal infection. To identify molecules that abrogate resistance to the most widely deployed class of antifungals, the azoles, we conducted a screen of 1,280 pharmacologically active compounds. Three out of seven hits that abolished azole resistance of a resistant mutant of the model yeast Saccharomyces cerevisiae and a clinical isolate of the leading human fungal pathogen Candida albicans were inhibitors of protein kinase C (PKC, which regulates cell wall integrity during growth, morphogenesis, and response to cell wall stress. Pharmacological or genetic impairment of Pkc1 conferred hypersensitivity to multiple drugs that target synthesis of the key cell membrane sterol ergosterol, including azoles, allylamines, and morpholines. Pkc1 enabled survival of cell membrane stress at least in part via the mitogen activated protein kinase (MAPK cascade in both species, though through distinct downstream effectors. Strikingly, inhibition of Pkc1 phenocopied inhibition of the molecular chaperone Hsp90 or its client protein calcineurin. PKC signaling was required for calcineurin activation in response to drug exposure in S. cerevisiae. In contrast, Pkc1 and calcineurin independently regulate drug resistance via a common target in C. albicans. We identified an additional level of regulatory control in the C. albicans circuitry linking PKC signaling, Hsp90, and calcineurin as genetic reduction of Hsp90 led to depletion of the terminal MAPK, Mkc1. Deletion of C. albicans PKC1 rendered fungistatic ergosterol biosynthesis inhibitors fungicidal and attenuated virulence in a murine model of systemic candidiasis. This work establishes a new role for PKC signaling in drug resistance, novel circuitry through which

  14. 人肝细胞癌及其配对非癌肝组织、正常肝组织中热休克蛋白Hsp90基因mRNA水平分析%Quantitative Analysis of hsp90 mRNA in Normal Liver, Hunan Hepatocellular Carcinoma and Paired Non-cancerous Liver Tissues

    Institute of Scientific and Technical Information of China (English)

    张杰; 刘军建; 张宁; 芮静安; 叶大雄; 雷道年; 金城; 周柔丽

    2001-01-01

    为定量分析和比较22对人肝细胞癌(HCC)及其配对非癌肝组织(PNL)和2例正常肝(NL)组织中热休克蛋白Hsp(heatshockprotein)90基因mRNA的表达水平,用狭缝杂交法检测hsp90βmRNA的表达;并进一步用以特异性复合cRNA为内参照的定量RT-PCR法对hsp90α和hspβmRNA的表达进行分析比较.狭缝杂交结果显示,hsp90βmRNA在13例(59.1%)PNL中的表达平均升高至NL的1.87倍;在21例(95.5%)HCC中的表达平均升高至NL的3.45倍;在20例(90.9%)HCC中的表达平均升高至PNL的2.75倍.以cRNA为内参照的mRNA定量RT-PCR结果显示,hsp90αmRNA在18例(81.8%)PNL中的表达平均升高至NL的3.06倍;在全部22例HCC中的表达平均升高至至PBL的2.08倍和NL的5.10倍.hsp90βmRNA仅在小部分(8例,36.4%)PNL中的表达轻度升高至NL的1.27倍,而在全部22例HCC中的表达显著升高至PNL的2.95倍和NL的2.52倍.hsp90α和hsp90β可能分别在人HCC发生、发展的不同阶段发挥不同的作用;以cRNA为内参照的定量RTPCR法是较狭缝杂交法更为灵敏、准确和快捷的mRNA定量分析方法.

  15. 温室粉虱和烟粉虱3个隐种中热激蛋白基因hsp70和hsp90含量的比较分析%Comparative analysis of the copy numbers of hsp70 and hsp90 in Trialeurodes vaporariorum and three cryptic species of Bemisia tabaci complex (Hemiptera: Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    韦姣; 吕志创; 王韧; 万方浩

    2014-01-01

    [目的]昆虫适应新环境的能力与其对温度的耐受能力密切相关.热激蛋白HSP70和HSP90具有提高生物体温度耐受性的功能.烟粉虱Bemisia tabaci (Gennadius)不同隐种和不同种粉虱对温度的适应能力有差异,这与它们的热激蛋白基因拷贝数的差异可能相关.[方法]利用实时荧光定量PCR方法,检测入侵型烟粉虱MED隐种和MEAM1隐种、本地型烟粉虱AsiaⅡ1隐种以及温室粉虱Trialeurodes vaporariorum (Westwood)基因组DNA中热激蛋白基因hsp70和hsp90的拷贝数.[结果]不同种类的粉虱和烟粉虱不同隐种体内的hsp70和hsp90的含量均有较大差异,其中hsp70和hsp90拷贝数在入侵型烟粉虱MED和MEAM1隐种中含量较其他两种均高,而在土著种AsiaⅡ1隐种中含量最低,在温室粉虱中居中.此外,相同物种雌雄成虫hsp70和hsp90的拷贝数也不同,雌虫hsp70和hsp90拷贝数约为雄虫的2倍.[结论]不同种粉虱及烟粉虱不同隐种的hsp70和hsp90的拷贝数可能与其耐热性差异相关.本研究为解释不同种粉虱、烟粉虱不同隐种及其不同性别的耐热性差异机制提供了进一步的依据.

  16. An Inducible Retroviral Expression System for Tandem Affinity Purification Mass-Spectrometry-Based Proteomics Identifies Mixed Lineage Kinase Domain-like Protein (MLKL) as an Heat Shock Protein 90 (HSP90) Client.

    Science.gov (United States)

    Bigenzahn, Johannes W; Fauster, Astrid; Rebsamen, Manuele; Kandasamy, Richard K; Scorzoni, Stefania; Vladimer, Gregory I; Müller, André C; Gstaiger, Matthias; Zuber, Johannes; Bennett, Keiryn L; Superti-Furga, Giulio

    2016-03-01

    Tandem affinity purification-mass spectrometry (TAP-MS) is a popular strategy for the identification of protein-protein interactions, characterization of protein complexes, and entire networks. Its employment in cellular settings best fitting the relevant physiology is limited by convenient expression vector systems. We developed an easy-to-handle, inducible, dually selectable retroviral expression vector allowing dose- and time-dependent control of bait proteins bearing the efficient streptavidin-hemagglutinin (SH)-tag at their N- or C termini. Concomitant expression of a reporter fluorophore allows to monitor bait-expressing cells by flow cytometry or microscopy and enables high-throughput phenotypic assays. We used the system to successfully characterize the interactome of the neuroblastoma RAS viral oncogene homolog (NRAS) Gly12Asp (G12D) mutant and exploited the advantage of reporter fluorophore expression by tracking cytokine-independent cell growth using flow cytometry. Moreover, we tested the feasibility of studying cytotoxicity-mediating proteins with the vector system on the cell death-inducing mixed lineage kinase domain-like protein (MLKL) Ser358Asp (S358D) mutant. Interaction proteomics analysis of MLKL Ser358Asp (S358D) identified heat shock protein 90 (HSP90) as a high-confidence interacting protein. Further phenotypic characterization established MLKL as a novel HSP90 client. In summary, this novel inducible expression system enables SH-tag-based interaction studies in the cell line proficient for the respective phenotypic or signaling context and constitutes a valuable tool for experimental approaches requiring inducible or traceable protein expression.

  17. Expression of HSP70 family and HSP90 family in skeletal muscles of transport stressed pigs%运输应激猪骨骼肌中热应激蛋白HSP70和HSP90家族的表达

    Institute of Scientific and Technical Information of China (English)

    鲍恩东; Sultan,KR; 等

    2001-01-01

    To demonstrate the expression of heat shock protein s(HSP)in skeletal muscles and to estimate the relationship between expression of HSP and pork quality, using Western blot four kinds of HSP which belongs to HSP70 family and HSP90 family respectively in porcine skeletal muscle tissues were determined after a long distance transport.All four HSP,namely HSP70,HSP72,HSP86 and HSP90,were regularly detected in M.longissimus dorsi and M.gluteus medius of both the transported and the cont rol group.The expression of HSP in control pigs showed that HSPs have some indep endent physiological from stress response undetermined functions.after 6 h trans port,the induction of the HSP70 and HSP72 in skeletal muscle tissues was slightly elevated(P>0.05).However,expression of the HSP 86 and the HSP90,especially HSP90,markedly decreased(P<0.01)in skelet al muscles.The results are implied that the reduction tendency of HSP90 fa mily is relative to pork quality and may serve as a potential marker for stress response.%利用Western blot技术,检测长途运输试验猪骨骼肌(背最长肌和臀大肌)中分属于HSP70家族和HSP90家族的4种应激蛋白(HSP70,HSP 72,HSP86和HSP90)的表达。所有运输应激猪和对照猪肌肉组织中均检测到了上述4种HSP。对照猪组织中HSP的表达说明HSP除了在受应激的细胞内行使生理功能外,还具有独立于应激刺激应答以外的其它作用。6 h的长途运输后,HSP的表达量明显不同,HSP70和HSP72在肌肉组织中的表达虽然有一定的增加,但统计学分析差异不显著(P>0.05);而HSP86和HSP90在骨骼肌中的表达明显下降,尤以HS P90下降最为显著(P<0.01)。提示HSP90家族成员与肉品品质相关,可能作为判断应激损伤的指征。

  18. Exosomes Isolated from Ascites of T-Cell Lymphoma-Bearing Mice Expressing Surface CD24 and HSP-90 Induce a Tumor-Specific Immune Response

    Science.gov (United States)

    Menay, Florencia; Herschlik, Leticia; De Toro, Julieta; Cocozza, Federico; Tsacalian, Rodrigo; Gravisaco, María José; Di Sciullo, María Paula; Vendrell, Alejandrina; Waldner, Claudia I.; Mongini, Claudia

    2017-01-01

    Extracellular vesicles (EVs), including endosome-derived nanovesicles (exosomes), are involved in cell–cell communication. Through transfer of their molecular contents, extracellular nanovesicles can alter the function of recipient cells. Due to these characteristics, EVs have shown potential as a new alternative for cancer immunotherapy. Tumor exosomes isolated from malignant ascites can activate dendritic cells, thereby priming the immune system to recognize and kill cancer cells. However, a suppressive role on tumor immune response has also been reported, suggesting that the neoplastic stage of carcinogenesis and the microenvironment where tumor cells grow may influence the amount of EVs released by the cell. This neoplastic stage and microenvironment may also impact EVs’ components such as proteins and miRNA, determining their biological behavior. Most T-cell lymphomas have an aggressive clinical course and poor prognosis. Consequently, complementary alternative therapies are needed to improve the survival rates achieved with conventional treatments. In this work, we have characterized EVs isolated from ascites of mice bearing a very aggressive murine T-cell lymphoma and have studied their immunogenic properties. Small EVs were isolated by differential centrifugation, ultrafiltration, and ultracentrifugation at 100,000 × g on a sucrose cushion. The EVs were defined as exosomes by their morphology and size analyzed by electron microscopy, their floating density on a sucrose gradient, as well as their expression of endosome marker proteins ALIX, TSG-101; the tetraspanins CD63, CD9, and CD81. In addition, they contain tumor antigens, the marker for malignancy CD24, the heat shock protein HSP-70, and an unusual surface expression of HSP-90 was demonstrated. The administration of EVs isolated from ascites (EVs A) into naïve-syngeneic mice induced both humoral and cellular immune responses that allowed the rejection of subsequent tumor challenges. However

  19. Dual inhibitory roles of geldanamycin on the c-Jun NH2-terminal kinase 3 signal pathway through suppressing the expression of mixed-lineage kinase 3 and attenuating the activation of apoptosis signal-regulating kinase 1 via facilitating the activation of Akt in ischemic brain injury.

    Science.gov (United States)

    Wen, X-R; Li, C; Zong, Y-Y; Yu, C-Z; Xu, J; Han, D; Zhang, G-Y

    2008-10-15

    It is well documented that heat-shock protein (hsp90) plays an essential role in maintaining stability and activity of its clients. Recent studies have shown that geldanamycin (GA), an inhibitor of hsp90, could decrease the protein of mixed-lineage kinase (MLK) 3 and activate Akt; our previous research documented that MLK3 and Akt and subsequent c-Jun N-terminal kinase (JNK) were involved in neuronal cell death in ischemic brain injury. Here, we investigated whether GA could decrease the protein of MLK3 and activate Akt in rat four-vessel occlusion ischemic model. Our results showed that global cerebral ischemia followed by reperfusion could enhance the association of hsp90 with MLK3, the association of hsp90 with Src, and JNK3 activation. As a result, GA decreased the protein of MLK3 and down-regulated JNK activation. On the other hand, Src kinase was activated and phosphorylated Cbl, which then recruited the p85 subunit of phosphatidylinositol 3-kinase (PI-3K), resulting in PI-3K activation, and as a consequence increased Akt activation, which inhibited ASK1 activation and down-regulated JNK3 activation. In summary, our results indicated that GA showed a dual inhibitory role on JNK3 activation and exerted strong neuroprotection in vivo and in vitro, which provides a new possible approach for stroke therapy.

  20. 热激蛋白Hsp90在调控裂殖酵母异染色质区基因沉默中的功能

    Institute of Scientific and Technical Information of China (English)

    李文珠; 余圣炜; 薛钰; 李丹丹; 靳全文

    2012-01-01

    鉴于高等生物中Hsp90与Argonaute蛋白的功能相关性,研究了裂殖酵母中Hsp90/Swo1与Ago1蛋白之间的相互关系以及对异染色质区基因沉默的影响。结果表明,裂殖酵母中Swo1蛋白通过与Ago1蛋白的相互作用,可以稳定Ago1蛋白,并且这种相互作用依赖于Swo1的N端和中央结构域以及Ago1的N端和PAZ结构域。在着丝粒的otr区和imr区,swo1+基因的突变会引起区域内基因沉默的解除,并且与RNAi组分双突变后(ago1Δ或dcr1Δ),基因沉默解除的效果加强。在交配型区,swo1+基因突变后也会引起显著的基因沉默解除现象。当swo1+基因突变后,依赖于Tas3的人工异染色质区基因沉默解除。研究发现了裂殖酵母中热激蛋白Hsp90的新功能,即参与异染色质区的基因沉默调控。

  1. Treatment of colon cancer cells using the cytosine deaminase/5-fluorocytosine suicide system induces apoptosis, modulation of the proteome, and Hsp90beta phosphorylation.

    Science.gov (United States)

    Negroni, Luc; Samson, Michel; Guigonis, Jean-Marie; Rossi, Bernard; Pierrefite-Carle, Valérie; Baudoin, Christian

    2007-10-01

    The bacterial cytosine deaminase (CD) gene, associated with the 5-fluorocytosine (5FC) prodrug, is one of the most widely used suicide systems in gene therapy. Introduction of the CD gene within a tumor induces, after 5FC treatment of the animal, a local production of 5-fluorouracil resulting in intratumor chemotherapy. Destruction of the gene-modified tumor is then followed by the triggering of an antitumor immune reaction resulting in the regression of distant wild-type metastasis. The global effects of 5FC on colorectal adenocarcinoma cells expressing the CD gene were analyzed using the proteomic method. Application of 5FC induced apoptosis and 19 proteins showed a significant change in 5FC-treated cells compared with control cells. The up-regulated and down-regulated proteins include cytoskeletal proteins, chaperones, and proteins involved in protein synthesis, the antioxidative network, and detoxification. Most of these proteins are involved in resistance to anticancer drugs and resistance to apoptosis. In addition, we show that the heat shock protein Hsp90beta is phosphorylated on serine 254 upon 5FC treatment. Our results suggest that activation of Hsp90beta by phosphorylation might contribute to tumor regression and tumor immunogenicity. Our findings bring new insights into the mechanism of the anticancer effects induced by CD/5FC treatment.

  2. Measurement of Nanomolar Dissociation Constants by Titration Calorimetry and Thermal Shift Assay – Radicicol Binding to Hsp90 and Ethoxzolamide Binding to CAII

    Directory of Open Access Journals (Sweden)

    Vilma Michailovienė

    2009-06-01

    Full Text Available The analysis of tight protein-ligand binding reactions by isothermal titration calorimetry (ITC and thermal shift assay (TSA is presented. The binding of radicicol to the N-terminal domain of human heat shock protein 90 (Hsp90aN and the binding of ethoxzolamide to human carbonic anhydrase (hCAII were too strong to be measured accurately by direct ITC titration and therefore were measured by displacement ITC and by observing the temperature-denaturation transitions of ligand-free and ligand-bound protein. Stabilization of both proteins by their ligands was profound, increasing the melting temperature by more than 10 ºC, depending on ligand concentration. Analysis of the melting temperature dependence on the protein and ligand concentrations yielded dissociation constants equal to 1 nM and 2 nM for Hsp90aN-radicicol and hCAII-ethoxzolamide, respectively. The ligand-free and ligand-bound protein fractions melt separately, and two melting transitions are observed. This phenomenon is especially pronounced when the ligand concentration is equal to about half the protein concentration. The analysis compares ITC and TSA data, accounts for two transitions and yields the ligand binding constant and the parameters of protein stability, including the Gibbs free energy and the enthalpy of unfolding.

  3. The crystal structure of the Sgt1-Skp1 complex: the link between Hsp90 and both SCF E3 ubiquitin ligases and kinetochores

    Science.gov (United States)

    Willhoft, Oliver; Kerr, Richard; Patel, Dipali; Zhang, Wenjuan; Al-Jassar, Caezar; Daviter, Tina; Millson, Stefan H.; Thalassinos, Konstantinos; Vaughan, Cara K.

    2017-01-01

    The essential cochaperone Sgt1 recruits Hsp90 chaperone activity to a range of cellular factors including SCF E3 ubiquitin ligases and the kinetochore in eukaryotes. In these pathways Sgt1 interacts with Skp1, a small protein that heterodimerizes with proteins containing the F-box motif. We have determined the crystal structure of the interacting domains of Saccharomyces cerevisiae Sgt1 and Skp1 at 2.8 Å resolution and validated the interface in the context of the full-length proteins in solution. The BTB/POZ domain of Skp1 associates with Sgt1 via the concave surface of its TPR domain using residues that are conserved in humans. Dimerization of yeast Sgt1 occurs via an insertion that is absent from monomeric human Sgt1. We identify point mutations that disrupt dimerization and Skp1 binding in vitro and find that the interaction with Skp1 is an essential function of Sgt1 in yeast. Our data provide a structural rationale for understanding the phenotypes of temperature-sensitive Sgt1 mutants and for linking Skp1-associated proteins to Hsp90-dependent pathways. PMID:28139700

  4. Cystein cathepsin and Hsp90 activities determine the balance between apoptotic and necrotic cell death pathways in caspase-compromised U937 cells.

    Science.gov (United States)

    Imre, Gergely; Dunai, Zsuzsanna; Petak, Istvan; Mihalik, Rudolf

    2007-10-01

    Caspase-inhibited cells induced to die may exhibit the traits of either apoptosis or necrosis or both, simultaneously. However, mechanisms regulating the commitment to these distinct forms of cell death are barely identified. We found that staurosporine induced both apoptotic and necrotic traits in U937 cells exposed to the caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp(OMe)-fluoromethylketone. Morphology and flow cytometry revealed that individual cells exhibited either apoptotic or necrotic traits, but not the mixed phenotype. Inhibition of cathepsin activity by benzyloxycarbonyl-Phe-Ala-fluoromethylketone rendered caspase-compromised cells resistant to staurosporine-induced apoptosis, but switched the cell death form to necrosis. Inhibition of heat shock protein 90 kDa (Hsp90) chaperon activity by geldanamycin conferred resistance to necrosis in caspase-compromised cells but switched the cell death form to apoptosis. Combination of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and geldanamycin halted the onset of both forms of cell death by saving mitochondrial trans-membrane potential and preventing acidic volume (lysosomes) loss. These effects of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and/or geldanamycin on cell death were restricted to caspase-inhibited cells exposed to staurosporine but influenced neither only the staurosporine-provoked apoptosis nor hydrogen peroxide (H2O2)-generated necrosis. Our results demonstrate that the staurosporine-induced death pathway bifurcates in caspase-compromised cells and commitment to apoptotic or necrotic phenotypes depends on cathepsin protease or Hsp90 chaperon activities.

  5. Structure–Activity Relationship in a Purine-Scaffold Compound Series with Selectivity for the Endoplasmic Reticulum Hsp90 Paralog Grp94

    Science.gov (United States)

    Patel, Hardik J.; Patel, Pallav D.; Ochiana, Stefan O.; Yan, Pengrong; Sun, Weilin; Patel, Maulik R.; Shah, Smit K.; Tramentozzi, Elisa; Brooks, James; Bolaender, Alexander; Shrestha, Liza; Stephani, Ralph; Finotti, Paola; Leifer, Cynthia; Li, Zihai; Gewirth, Daniel T.; Taldone, Tony; Chiosis, Gabriela

    2015-01-01

    Grp94 is involved in the regulation of a restricted number of proteins and represents a potential target in a host of diseases, including cancer, septic shock, autoimmune diseases, chronic inflammatory conditions, diabetes, coronary thrombosis, and stroke. We have recently identified a novel allosteric pocket located in the Grp94 N-terminal binding site that can be used to design ligands with a 2-log selectivity over the other Hsp90 paralogs. Here we perform extensive SAR investigations in this ligand series and rationalize the affinity and paralog selectivity of choice derivatives by molecular modeling. We then use this to design 18c, a derivative with good potency for Grp94 (IC50 = 0.22 μM) and selectivity over other paralogs (>100- and 33-fold for Hsp90α/β and Trap-1, respectively). The paralog selectivity and target-mediated activity of 18c was confirmed in cells through several functional readouts. Compound 18c was also inert when tested against a large panel of kinases. We show that 18c has biological activity in several cellular models of inflammation and cancer and also present here for the first time the in vivo profile of a Grp94 inhibitor. PMID:25901531

  6. The split Renilla luciferase complementation assay is useful for identifying the interaction of Epstein-Barr virus protein kinase BGLF4 and a heat shock protein Hsp90.

    Science.gov (United States)

    Wang, J; Guo, W; Long, C; Zhou, H; Wang, H; Sun, X

    2016-03-01

    Protein-protein interactions can regulate different cellular processes, such as transcription, translation, and oncogenic transformation. The split Renilla luciferase complementation assay (SRLCA) is one of the techniques that detect protein-protein interactions. The SRLCA is based on the complementation of the LN and LC non-functional halves of Renilla luciferase fused to possibly interacting proteins which after interaction form a functional enzyme and emit luminescence. The BGLF4 of Epstein-Barr virus (EBV) is a viral protein kinase that is expressed during the early and late stages of lytic cycles, which can regulate multiple cellular and viral substrates to optimize the DNA replication environment. The heat shock protein Hsp90 is a molecular chaperone that maintains the integrity of structure and function of various interacting proteins, which can form a complex with BGLF4 and stabilize its expression in cells. The interaction between BGLF4 and Hsp90 could be specifically detected through the SRLCA. The region of aa 250-295 of BGLF4 is essential for the BGLF4/Hsp90 interaction and the mutation of Phe-254, Leu-266, and Leu-267 can disrupt this interaction. These results suggest that the SRLCA can specifically detect the BGLF4/Hsp90 interaction and provide a reference to develop inhibitors that disrupt the BGLF4/Hsp90 interaction.

  7. Cloning of a putative heat shock protein 90 gene from Spirulina innermongoliansis and construction of three pro-integration expression vector%内蒙古螺旋藻HSP90基因的克隆及三亲接合表达载体构建

    Institute of Scientific and Technical Information of China (English)

    周博; 李博生

    2011-01-01

    内蒙古螺旋藻是一种原产于内蒙古碱湖,品质优良、中温适应型的螺旋藻品种,但因发现较晚,生长环境特殊等原因,对其分子遗传学等基础研究相对滞后.提高其耐热性能够扩大养殖范围,降低养殖成本,具有很大的应用价值.研究表明热激蛋白在藻类抗高温胁迫中起着重要作用.本研究采用PCR技术得到内蒙古螺旋藻HSP90基因序列,并对基因及其编码蛋白序列进行了初步分析;同时,根据蓝藻遗传转化需要,构建了三亲接合转移的穿梭表达载体,该载体起始密码子ATG与目的基因HSP90相距6bp,含有进行三亲结合转移所需的蓝藻复制起始区、Bom基因、启动子(BetaP)、氯霉素抗性基因(Cm)及目的基因HSP90.研究结果为构建耐热内蒙古螺旋藻转基因新品系等奠定了基础.%Spirulina innermongoliansis is a high quality variety with normal temperature adaptability, which was found in salt lake in Inner Mongolia. Because of its later discovering history, and its special living conditions and other related reasons, S. innermongoliansis have not be widely studied and exploited in molecular genetics. Improving its heat resistance could expand its breeding range and reduce the farming costs. Some researches showed that heat shock protein played an important role in heat resistance of algae. This present study used PCR technology to gain HSP90 gene sequences in S. innermongoliansis, and then analyzed the gene sequence and its encoding protein gene sequence. Meanwhile, according to the genetic transformation of algae, we constructed a three pro-integration expression vector, whose initiation codon ATG was 6 bp away from HSP90 gene. Three pro-integration expression vector had a cyanobacterial replication origin, a Bom gene, a promoter (BetaP) and a chloramphenicol resistance gene (Cm), which was essential to three pro-integration, then connected the gene HSP90. Therefore, this research was a necessary foundation

  8. Differences in the Ovine HSP90AA1 Gene Expression Rates Caused by Two Linked Polymorphisms at Its Promoter Affect Rams Sperm DNA Fragmentation under Environmental Heat Stress Conditions

    Science.gov (United States)

    González, Carmen; Pérez-Guzmán, M. Dolores; Garde, J. Julián; García-Álvarez, Olga; Maroto-Morales, Alejandro; Calvo, Jorge H.; Serrano, M. Magdalena

    2015-01-01

    Heat shock (HS) is one of the best-studied exogenous cellular stresses. Almost all tissues, cell types, metabolic pathways and biochemical reactions are affected in greater or lesser extent by HS. However, there are some especially thermo sensible cellular types such as the mammalian male germ cells. The present study examined the role of three INDELs in conjunction with the -660G/C polymorphism located at the HSP90AA1 promoter region over the gene expression rate under HS. Specially, the -668insC INDEL, which is very close to the -660G/C transversion, is a good candidate to be implied in the transcriptional regulation of the gene by itself or in a cooperative way with this SNP. Animals carrying the genotype II-668 showed higher transcription rates than those with ID-668 (FC = 3.07) and DD-668 (FC = 3.40) genotypes for samples collected under HS. A linkage between gene expression and sperm DNA fragmentation was also found. When HS conditions were present along or in some stages of the spermatogenesis, alternative genotypes of the -668insC and -660G/C mutations are involved in the effect of HS over sperm DNA fragmentation. Thus, unfavorable genotypes in terms of gene expression induction (ID-668GC-660 and DD-668GG-660) do not produce enough mRNA (stored as messenger ribonucleoprotein particles) and Hsp90α protein to cope with future thermal stress which might occur in posterior stages when transcriptional activity is reduced and cell types and molecular processes are more sensible to heat (spermatocytes in pachytene and spermatids protamination). This would result in the impairment of DNA packaging and the consequent commitment of the events occurring shortly after fertilization and during embryonic development. In the short-term, the assessment of the relationship between sperm DNA fragmentation sensitivity and ram’s fertility will be of interest to a better understanding of the mechanisms of response to HS and its consequences on animal production and

  9. Effect of inhibition of the Ubiquitin-Proteasome System and Hsp90 on growth and survival of Rhabdomyosarcoma cells in vitro

    Directory of Open Access Journals (Sweden)

    Peron Marica

    2012-06-01

    Full Text Available Abstract Background The ubiquitin-proteasome system (UPS and the heat shock response (HSR are two critical regulators of cell homeostasis, as their inhibition affects growth and survival of normal cells, as well as stress response and invasiveness of cancer cells. We evaluated the effects of the proteasome inhibitor Bortezomib and of 17-DMAG, a competitive inhibitor of Hsp90, in rhabdomyosarcoma (RMS cells, and analyzed the efficacy of single-agent exposures with combination treatments. Methods To assess cytotoxicity induced by Bortezomib and 17-DMAG in RMS cells, viability was measured by MTT assay after 24, 48 and 72 hours. Western blotting and immunofluorescence analyses were carried out to elucidate the mechanisms of action. Apoptosis was measured by FACS with Annexin-V-FITC and Propidium Iodide. Results Bortezomib and 17-DMAG, when combined at single low-toxic concentrations, enhanced growth inhibition of RMS cells, with signs of autophagy that included intensive cytoplasmic vacuolization and conversion of cytosolic LC3-I protein to its autophagosome-associated form. Treatment with lysosomal inhibitor chloroquine facilitates apoptosis, whereas stimulation of autophagy by rapamycin prevents LC3-I conversion and cell death, suggesting that autophagy is a resistance mechanism in RMS cells exposed to proteotoxic drugs. However, combination treatment also causes caspase-dependent apoptosis, PARP cleavage and Annexin V staining, as simultaneous inhibition of both UPS and HSR systems limits cytoprotective autophagy, exacerbating stress resulting from accumulation of misfolded proteins. Conclusion The combination of proteasome inhibitor Bortezomib with Hsp90 inhibitor 17-DMAG, appears to have important therapeutic advantages in the treatment of RMS cells compared with single-agent exposure, because compensatory survival mechanisms that occur as side effects of treatment may be prevented.

  10. Pre-clinical efficacy of PU-H71, a novel HSP90 inhibitor, alone and in combination with bortezomib in Ewing sarcoma.

    Science.gov (United States)

    Ambati, Srikanth R; Lopes, Eloisi Caldas; Kosugi, Kohji; Mony, Ullas; Zehir, Ahmet; Shah, Smit K; Taldone, Tony; Moreira, Andre L; Meyers, Paul A; Chiosis, Gabriela; Moore, Malcolm A S

    2014-03-01

    Ewing sarcoma is characterized by multiple deregulated pathways that mediate cell survival and proliferation. Heat shock protein 90 (HSP90) is a critical component of the multi-chaperone complexes that regulate the disposition and activity of a large number of proteins involved in cell-signaling systems. We tested the efficacy of PU-H71, a novel HSP90 inhibitor in Ewing sarcoma cell lines, primary samples, benign mesenchymal stromal cells and hematopoietic stem cells. We performed cell cycle analysis, clonogenic assay, immunoblot analysis and reverse phase protein array in Ewing cell lines and in vivo experiments in NSG and nude mice using the A673 cell line. We noted a significant therapeutic window in the activity of PU-H71 against Ewing cell lines and benign cells. PU-H71 treatment resulted in G2/M phase arrest. Exposure to PU-H71 resulted in depletion of critical proteins including AKT, pERK, RAF-1, c-MYC, c-KIT, IGF1R, hTERT and EWS-FLI1 in Ewing cell lines. Our results indicated that Ewing sarcoma tumor growth and the metastatic burden were significantly reduced in the mice injected with PU-H71 compared to the control mice. We also investigated the effects of bortezomib, a proteasome inhibitor, alone and in combination with PU-H71 in Ewing sarcoma. Combination index (CI)-Fa plots and normalized isobolograms indicated synergism between PU-H71 and bortezomib. Ewing sarcoma xenografts were significantly inhibited when mice were treated with the combination compared to vehicle or either drug alone. This provides a strong rationale for clinical evaluation of PU-H71 alone and in combination with bortezomib in Ewing sarcoma.

  11. 热激蛋白Hsp90在调控裂殖酵母异染色质区基因沉默中的功能%Function of heat shock protein 90 (Hsp90) in heterochromatic gene silencing in fission yeast

    Institute of Scientific and Technical Information of China (English)

    李文珠; 余圣炜; 薛钰; 李丹丹; 靳全文

    2012-01-01

    Given that Hsp90 functionally correlates with Argonaute in higher eukaryotes, we examined the interaction between Hsp90 (Swol) and Agoland the function of Hsp90 on heterochromatic gene silencing in fission yeast Schizosaccharomyces pombe. The results showed that Swol could stabilize Agol through interaction with Agol in fission yeast. The interaction between Swol and Agol depends on N domain and the central region of Swol, as well as the N and PAZ domains of Agol. The centromeric silencing was alleviated in the swol-26 mutant, but the silencing of reporter gene at telomere and rDNA regions remained unchanged. Double mutants of swol-26 dcrlA and swo1-26 agolA showed enhanced silencing defects at centromeric regions. In the mating type region, we observed a significant derepression ofgene silencing in the swol-26 mutant. The artificial RITS complex-dependent silencing system was also defective in the swol-26 mutant. Our results found a new role of lisp90 in gene silencing at heterochromatin regions in S. pombe.%鉴于高等生物中Hsp90与Argonaute蛋白的功能相关性,研究了裂殖酵母中Hsp90/Swo1与Ago1蛋白之间的相互关系以及对异染色质区基因沉默的影响。结果表明,裂殖酵母中Swo1蛋白通过与Ago1蛋白的相互作用,可以稳定Ago1蛋白,并且这种相互作用依赖于Swo1的N端和中央结构域以及Ago1的N端和PAZ结构域。在着丝粒的otr区和imr区,swo1+基因的突变会引起区域内基因沉默的解除,并且与RNAi组分双突变后(ago1Δ或dcr1Δ),基因沉默解除的效果加强。在交配型区,swo1+基因突变后也会引起显著的基因沉默解除现象。当swo1+基因突变后,依赖于Tas3的人工异染色质区基因沉默解除。研究发现了裂殖酵母中热激蛋白Hsp90的新功能,即参与异染色质区的基因沉默调控。

  12. B型烟粉虱和温室白粉虱热激蛋白90基因(hsp90)的全长cDNA克隆与系统发育分析%cDNA cloning and phylogenetic analysis of the heat shock protein 90 gene (hsp90) in two whiteflies,Bemisia tabaci (Gennadius) biotype B and Trialeurodes vaporariorum (Westwood) (Homoptera:Aleyrodidae)

    Institute of Scientific and Technical Information of China (English)

    余昊; 万方浩

    2009-01-01

    B型烟粉虱Bemisia tabaci (Gennadius) biotype B和温室白粉虱Trialeurodes vaporariorum均为全球普遍发生的重要害虫.本研究以其他昆虫热激蛋白90基因(hsp90)保守区域设计兼并引物扩增两种粉虱hsp90中间片段,然后利用RACE技术获得全长cDNA.温室白粉虱hsp90全长cDNA的开放性阅读框2 166 bp,编码722个氨基酸;烟粉虱hsp90全长cDNA的开放性阅读框2 160 bp,编码720个氨基酸.两种粉虱HSP90的完整氨基酸序列相似性高达92.94%,并均具有定义HSP90家族签名序列的5个氨基酸保守区域和末尾基序"MEEVD".通过real-time PCR技术,探测到两个基因在mRNA水平上皆能高温诱导表达.采用昆虫纲所有完整HSP90氨基酸序列进行Kimura双参数遗传距离分析并构建NJ进化树,结果显示hsp90在昆虫纲低级阶元水平和高级阶元水平系统进化上能得到一个较理想结果.本研究结果为B型烟粉虱和温室白粉虱抗逆适应性研究提供基础,并进一步验证保守的功能基因hsp90可以作为研究生物系统发育的手段之一.

  13. Endoplasmic Reticulum-resident Heat Shock Protein 90 (HSP90) Isoform Glucose-regulated Protein 94 (GRP94) Regulates Cell Polarity and Cancer Cell Migration by Affecting Intracellular Transport.

    Science.gov (United States)

    Ghosh, Suman; Shinogle, Heather E; Galeva, Nadezhda A; Dobrowsky, Rick T; Blagg, Brian S J

    2016-04-15

    Heat shock protein 90 (HSP90) is a molecular chaperone that is up-regulated in cancer and is required for the folding of numerous signaling proteins. Consequently, HSP90 represents an ideal target for the development of new anti-cancer agents. The human HSP90 isoform, glucose-regulated protein 94 (GRP94), resides in the endoplasmic reticulum and regulates secretory pathways, integrins, and Toll-like receptors, which contribute to regulating immunity and metastasis. However, the cellular function of GRP94 remains underinvestigated. We report that GRP94 knockdown cells are defective in intracellular transport and, consequently, negatively impact the trafficking of F-actin toward the cellular cortex, integrin α2 and integrin αL toward the cell membrane and filopodia, and secretory vesicles containing the HSP90α-AHA1-survivin complex toward the leading edge. As a result, GRP94 knockdown cells form a multipolar spindle instead of bipolar morphology and consequently manifest a defect in cell migration and adhesion.

  14. Ahsa1 and Hsp90 activity confers more severe craniofacial phenotypes in a zebrafish model of hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR

    Directory of Open Access Journals (Sweden)

    Kelly Sheehan-Rooney

    2013-09-01

    The severity of most human birth defects is highly variable. Our ability to diagnose, treat and prevent defects relies on our understanding of this variability. Mutation of the transcription factor GATA3 in humans causes the highly variable hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR syndrome. Although named for a triad of defects, individuals with HDR can also exhibit craniofacial defects. Through a forward genetic screen for craniofacial mutants, we isolated a zebrafish mutant in which the first cysteine of the second zinc finger of Gata3 is mutated. Because mutation of the homologous cysteine causes HDR in humans, these zebrafish mutants could be a quick and effective animal model for understanding the role of gata3 in the HDR disease spectrum. We demonstrate that, unexpectedly, the chaperone proteins Ahsa1 and Hsp90 promote severe craniofacial phenotypes in our zebrafish model of HDR syndrome. The strengths of the zebrafish system, including rapid development, genetic tractability and live imaging, make this an important model for variability.

  15. Effect of Heat - shock Protein 90 (HSP90) on Sperm Motility durig Cooling of Boar Spermatozoa%精液冷却过程中应激蛋白90对猪精子活动力的影响

    Institute of Scientific and Technical Information of China (English)

    金一; 魏世宝; 王晓明; 金花子

    2006-01-01

    公猪的精子对冷休克高度敏感,在迅速冷却时失去活力,称之为“冷休克”,而应激蛋白90(HSP90)外源的低表达阻碍细胞周期和减弱冷休克反应。对受精来说,精子运动性是一个重要的参数,HSP90和精子运动有很大的联系。因此,研究猪精子冷却过程中HSP90与精子运动力的关系是很必要的。

  16. The Interactions of TPR Domains of Ppp5c/TTC16 with Hsp70/90 and Their Influence on the Cell Cycle%Ppp5c和TTC16基因的TPR结构域与Hsp70、Hsp90蛋白的相互作用及对细胞周期的影响

    Institute of Scientific and Technical Information of China (English)

    刘德康; 李蕾; 陈霞; 唐超; 李建民

    2012-01-01

    目的:研究Ppp5c及TTC16基因的TPR (tetratricopeptide repeat)结构域短片段和Hsp70及Hsp90家族蛋白的相互做用,及其过表达时细胞周期的影响.方法:通过生物信息学的分析及PCR的方法,克隆Ppp5c及TTC16基因的TPR结构域以及HSPAIA、HsP90AA1的全长基因,并连入酵母双杂交载体,通过ClonTech的酵母双杂交实验体系研究蛋白和蛋白之问的相互作用.把Ppp5c及TIC16基因的TPR结构域克隆入真核表达栽体,构架稳定表达Ppp5c及TTC16基因的TPR结构域的MCF-7细胞系,并通过流式细胞实验观察细胞周期.结果:Ppp5c及TTC16基因的TPR结构域能与HSPAIA或HsP90AAI发生相互作用.Ppp5c及TTC16基因的TPR结构域在MCF-7中的过表达能严重影响细胞周期,引起细胞凋亡和S期阻滞.结论:本实验初步揭示了不同蛋白的TPR结构域在与Hsp70及Hsp90蛋白的相互作用性质的异同点以及其过表达对细胞周期的影响,为全面理解TPR结构域的功能、PPP5c以及TTC16蛋白在细胞内的功能奠定了前期实验基础.%Objective: To investigate the interactions between the TPR (tetratricopeptide repeat) domains of Ppp5c/TTC16 and protein, of Hsp70/Hsp90, to study the effect of the overexpression of TPR domains of Ppp5c/TTC16 on cell cycle in MCF-7 cell lines. Methods: After being analyzed by online informatics tools, the TPR domains of Ppp5c/TTC16 and full-length of HSPA1A/HSP90AA1 genes were respectively sub-cloned into two separate vectors of the yeast two-hybrid system provided by ClonTech to confirm the protein-protein interactions. The TPR domains of Ppp5c/TTC16 were sub-cloned into eukaryotic expression vectors which were stably transfected into MCF-7 cell-lines, whose cell cycle was then examined by flow cytometry. Results: The TPR domains of Ppp5c/TTC16 interacted with proteins of HSPA1A/HSP90AA1. A large amount of apoptosis was detected when the TPR domains of Ppp5c over-expressed in MCF-7 cell line, and the cell cycle was

  17. Caracterización in silico de las proteínas del choque térmico Hsp70 y Hsp90 deBemisia tabaci (Hemiptera: Aleyrodidae y su posible actividad adaptativa

    Directory of Open Access Journals (Sweden)

    Eneida Torres Cabra

    2014-06-01

    Full Text Available La mosca blanca, Bemisia tabaci (Hemiptera: Aleyrodidae es una de las plagas más destructivas e invasivas en el mundo, ataca una gran cantidad de cultivos. Se adapta fácilmente a plantas hospederas y a nuevas regiones geográficas, lo que sugiere el desarrollo de mecanismos de control a daños producidos por factores estresantes. Las proteínas Hsp se expresanen los organismos como mecanismo de defensa, actúan como chaperonas en el correcto ensamblaje de las proteínas. En este estudio se realizó una caracterizaciónin silico de las proteínas Hsp70 y Hsp90 de B. tabaci, secuencias obtenidas de NCBI. La determinaciónde los perfiles de hidrofobicidad, polaridad, accesibilidady flexibilidad se obtuvieron con “ProScale” de ExPASy, el perfil de antigenicidad con JaMBW. La secuencia aminoacídica se analizó con GOR IV y SOPMA y la composición de aminoácidos con ProtParam. Para analizar el peso molecular, índice deinestabilidad, índice alifático y gradiente hidropático,con GRAVY. La estructura terciaria se obtuvo con HHpred, y ESyPred3D. Para validar las estructuras 3D se utilizó Procheck, What_check y errat. Hsp70 y Hsp90 de B. tabaci presentan valores bajos de hidrofobicidady altos de polaridad, flexibilidad y accesibilidad, características que le permiten a las proteínas extender su capacidad como chaperonas. La Hsp70tiene una estructura secundaria compuesta por 41-45% alfa hélices, 30-43% coil y menos del 6% en hoja plegada y la Hsp90 por 52 y 53% hélices, 26-34% coily 6% hoja plegada. Las Hsp juegan un rol importante en los insectos debido a su tamaño y corto ciclo de vida, pues la temperatura influye en su distribución y abundancia.

  18. HSP90、CDC37、CRM1作为P16INK4A活性调节剂在大鼠肝癌发生与人类肝癌中的作用

    Institute of Scientific and Technical Information of China (English)

    Pascale; R.; M.; Simile; M.; M.; Calvisi; D.; F.; 宋平(译); 陈云茹(校)

    2006-01-01

    目前有证据表明,人工诱导的在遗传学上有抵抗肝癌形成的挪威棕鼠(BN大鼠)肝内的瘤结节并不易于促进肝细胞肝癌的发生。作者发现,与在接受2-乙酰氨基芴治疗期间或治疗结束时均对肝癌易感的Fisher 344(F344)大鼠相比,经过阻断肝细胞增殖的二乙基亚硝胺/2~乙酰氨基芴/部分肝切除治疗后,BN大鼠更高地表达了谷胱甘肽-S-转移酶7—7(+)肝细胞,然而在完成肝细胞修复生长后,DNA的合成在BN大鼠中有所下降,而F344大鼠却未见下降。在F344大鼠的肝硬化前期、结节期和肝细胞肝癌的细胞中,P16INK4A HSP90和CDC37基因表达上调,CDC37-CDK4复合物的表达上调,而P16INK4A -CDK4复合物下调,但这些参数在BN大鼠并无明显变化。E2F4在两种大鼠病变中的表达无明显差异,但CRM1的表达和E2F4-CRM1复合物的水平在F344大鼠中表达较高。在人肝细胞肝癌中,P16INK4A显著的高表达与HSP90、CDC37、E2F4和CRM1适度的高表达相关时,肝癌预后较好。

  19. Epsilon PKC increases brain mitochondrial SIRT1 protein levels via heat shock protein 90 following ischemic preconditioning in rats.

    Directory of Open Access Journals (Sweden)

    John W Thompson

    Full Text Available Ischemic preconditioning is a neuroprotective mechanism whereby a sublethal ischemic exposure is protective against a subsequent lethal ischemic attack. We previously demonstrated that SIRT1, a nuclear localized stress-activated deacetylase, is vital for ischemic preconditioning neuroprotection. However, a recent study demonstrated that SIRT1 can also localize to the mitochondria. Mitochondrial localized SIRT1 may allow for a direct protection of mitochondria following ischemic preconditioning. The objective of this study was to determine whether ischemic preconditioning increases brain mitochondrial SIRT1 protein levels and to determine the role of PKCɛ and HSP90 in targeting SIRT1 to the mitochondria. Here we report that preconditioning rats, with 2 min of global cerebral ischemia, induces a delayed increase in non-synaptic mitochondrial SIRT1 protein levels which was not observed in synaptic mitochondria. This increase in mitochondrial SIRT1 protein was found to occur only in neuronal cells and was mediated by PKCε activation. Inhibition of HSP90, a protein chaperone involved in mitochondrial protein import, prevented preconditioning induced increases in mitochondrial SIRT1 and PKCε protein. Our work provides new insights into a possible direct role of SIRT1 in modulating mitochondrial function under both normal and stress conditions, and to a possible role of mitochondrial SIRT1 in activating preconditioning induced ischemic tolerance.

  20. 基于分子片段的药物设计:热休克蛋白90抑制剂的发现与开发研究进展%Fragment-based drug design: discovery and development of HSP90 inhibitor

    Institute of Scientific and Technical Information of China (English)

    何小羊; 王升启

    2014-01-01

    分子伴侣热休克蛋白90(HSP90)在肿瘤细胞中处于活化状态,呈现高表达,在维持肿瘤细胞生存、增殖、侵袭、转移,以及血管增生过程中具有关键作用,作用于HSP90 N端ATP结合域的天然产物格尔德霉素及其衍生物在体内对多种肿瘤具有抑制活性,因此,HSP90已成为抗肿瘤药物研发的热门靶点.基于片段的药物设计是HSP90抑制剂开发的重要策略,已发现了众多结构新颖的高效率配体的小分子片段,依据结构信息进行优化,开发了许多具有良好活性的先导物乃至临床候选物.本文分析了一些基于片段方法的HSP90抑制剂开发案例,并基于X线衍射晶体结构信息,综述了这些从片段到先导物乃至候选药的理性优化过程.

  1. Novel Functional Association of Serine Palmitoyltransferase Subunit 1-A Peptide in Sphingolipid Metabolism with Cytochrome P4501A1 Transactivation and Proliferative Capacity of the Human Glioma LN18 Brain Tumor Cell Line

    Directory of Open Access Journals (Sweden)

    J. Stewart

    2006-09-01

    Full Text Available Some chemical modulators of cytochrome P4501A1, Cyp1A1, expression also perturb the activity of serine palmitoyltransferase, SPT, a heterodimeric protein responsible for catalyzing the first reaction in sphingolipid biosynthesis. The effect of altered SPT activity on Cyp1A1 expression has generally been attributed to changes in the composition of bioactive sphingolipids, generated downstream in the SPT metabolic pathway, but the precise mechanism remains poorly defined. A generally accepted model for chemical-induced transactivation of the Cyp1A1 gene involves intracellular signaling mediated by proteins including the arylhydrocarbon receptor, AhR, whose interaction with the 90 kilo Dalton heat shock protein, Hsp90, is essential for maintaining a high affinity ligandbinding receptor conformation. Because ligand-induced Cyp1A1 expression is important in the bioactivation of environmentally relevant compounds to genotoxic derivatives capable of perturbing cellular processes, binding to Hsp90 represents an important regulatory point in the cytotoxicity process. In the present study, based on evidence that indicates subunit 1 of serine palmitoyltransferase, SPT1, interacts with Hsp90, both ligand-induced Cyp1A1 transactivation and capacity for proliferation were evaluated using the wild type Glioma LN18 human brain cancer cell line and its recombinant counterparts expressing green fluorescent SPT1 fusion proteins. Exposure to the prototypical Cyp1A1 inducer, 3-methylcholanthrene, 3-MC, resulted in the translocation of SPT1 from a primarily cytoplasmic domain to sites of focal adhesion complexes. Immunolabel for Hsp90, which was dispersed throughout the cell, became primarily cytoplasmic, while the distribution of AhR remained unaffected. When compared to the wild type, cells transfected with recombinant SPT1-GFP vectors had significantly attenuated levels of 3-MC-induced Cyp1A1 mRNA, as determined by quantitative reverse transcription PCR. Although

  2. A proteomic study of the differential protein expression in MDBK cells after bovine herpesvirus type 1 infection (BHV-1) strain treatment.

    Science.gov (United States)

    Guo, Li; Yang, Yanling; Liu, Linna; Liao, Peng; Wen, Yongjun; Wu, Hua; Cheng, Shipeng

    2015-01-01

    Different BHV-1 strains, such as the virulent IBRV LN01/08 strains and the attenuated vaccine strain IBRV LNM, produces different clinical immune responses; however, the study of the differential protein expression in Madin-Darby bovine kidney (MDBK) cells after BHV-1-infection still remains unclear. Here, we applied a comparative proteomic strategy, based on 2D and MALDI-TOF/MS platforms, to examine the differential expression of proteins in MDBK cells that were treated and not treated with virulent IBRV LN01/08 and attenuated IBRV LNM strains. A total of eight differential proteins, including pyruvate kinase, heat shock protein (HSP) 90 (HSP90AA1 and HSP90AB1), annexin A, albumin (ALB), scinderin (SCIN), tubulin (alpha 1a) and vimentin (VIM), were identified. Among these proteins, pyruvate kinase, and HSP90 (HSP90AB1), tubulin and vimentin were identified in the virulent IBRV LN01/08 strain group, but were not identified in the attenuated IBRV LNM group. These results play an important role in tumor formation and development, cell migration, tumor cell line apoptosis, cell invasion and viral infection. The HSP90 (HSP90AA1) protein was identified in the control group and the attenuated IBRV LNM-infected group. Most studies have shown that HSP90 proteins were more of a cancer gene target, and inhibiting its function would result to oncogene degradation during cancer treatment. On the other hand, ALB is associated to cell differentiation, apoptosis, necrosis, cell death, viral infection, autophagy, interstitial tissue inflammation, and cell survival. These results provide a theoretical basis for the systematic understanding of BHV-1-infection mechanisms and BHV-1-induced immune responses.

  3. Foreign Language Study and the Brain.

    Science.gov (United States)

    LeLoup, Jean W.; Ponterio, Robert

    2003-01-01

    Provides information on foreign language study and the brain and highlights a Web site called Foreign Language Study and the Brain. The Web site is in Spanish and English and provides information on brain-sensitive activities that foster memory storage and language retrieval. Recent research on the brain and general recommendations for classroom…

  4. Brains studying brains: look before you think in vision

    Science.gov (United States)

    Zhaoping, Li

    2016-06-01

    Using our own brains to study our brains is extraordinary. For example, in vision this makes us naturally blind to our own blindness, since our impression of seeing our world clearly is consistent with our ignorance of what we do not see. Our brain employs its ‘conscious’ part to reason and make logical deductions using familiar rules and past experience. However, human vision employs many ‘subconscious’ brain parts that follow rules alien to our intuition. Our blindness to our unknown unknowns and our presumptive intuitions easily lead us astray in asking and formulating theoretical questions, as witnessed in many unexpected and counter-intuitive difficulties and failures encountered by generations of scientists. We should therefore pay a more than usual amount of attention and respect to experimental data when studying our brain. I show that this can be productive by reviewing two vision theories that have provided testable predictions and surprising insights.

  5. Study Shows How Zika Attacks Infant Brain

    Science.gov (United States)

    ... gov/news/fullstory_162514.html Study Shows How Zika Attacks Infant Brain Virus can copy itself thousands ... New research paints a chilling portrait of how Zika ravages the infant brain. Scientists from the U.S. ...

  6. Magnetoencephalography in the study of brain dynamics.

    Science.gov (United States)

    Pizzella, Vittorio; Marzetti, Laura; Della Penna, Stefania; de Pasquale, Francesco; Zappasodi, Filippo; Romani, Gian Luca

    2014-01-01

    To progress toward understanding of the mechanisms underlying the functional organization of the human brain, either a bottom-up or a top-down approach may be adopted. The former starts from the study of the detailed functioning of a small number of neuronal assemblies, while the latter tries to decode brain functioning by considering the brain as a whole. This review discusses the top-down approach and the use of magnetoencephalography (MEG) to describe global brain properties. The main idea behind this approach is that the concurrence of several areas is required for the brain to instantiate a specific behavior/functioning. A central issue is therefore the study of brain functional connectivity and the concept of brain networks as ensembles of distant brain areas that preferentially exchange information. Importantly, the human brain is a dynamic device, and MEG is ideally suited to investigate phenomena on behaviorally relevant timescales, also offering the possibility of capturing behaviorally-related brain connectivity dynamics.

  7. Regulation of Toll-like receptor 2 interaction with Ecgp96 controls Escherichia coli K1 invasion of brain endothelial cells

    Science.gov (United States)

    Krishnan, Subramanian; Chen, Shuang; Turcatel, Gianluca; Arditi, Moshe; Prasadarao, Nemani V.

    2012-01-01

    SUMMARY The interaction of outer membrane protein A (OmpA) with its receptor, Ecgp96 (a homologue of Hsp90β) is critical for the pathogenesis of E. coli K1 meningitis. Since Hsp90 chaperones Toll-like receptors (TLRs), we examined the role of TLRs in E. coli K1 infection. Herein, we show that newborn TLR2−/− mice are resistant to E. coli K1 meningitis, while TLR4−/− mice succumb to infection sooner. In vitro, OmpA+ E. coli infection selectively upregulates Ecgp96 and TLR2 in human brain microvascular endothelial cells (HBMEC), whereas OmpA− E. coli upregulates TLR4 in these cells. Furthermore, infection with OmpA+ E. coli causes Ecgp96 and TLR2 translocate to the plasma membrane of HBMEC as a complex. Immunoprecipitation studies of the plasma membrane fractions from infected HBMEC reveal that the C-termini of Ecgp96 and TLR2 are critical for OmpA+ E. coli invasion. Knockdown of TLR2 using siRNA results in inefficient membrane translocation of Ecgp96 and significantly reduces invasion. In addition, the interaction of Ecgp96 and TLR2 induces a bipartite signal, one from Ecgp96 through PKC-α while the other from TLR2 through MyD88, ERK1/2 and NF-κB. This bipartite signal ultimately culminates in the efficient production of NO, which in turn promotes E. coli K1 invasion of HBMEC. PMID:22963587

  8. Brain-Science Based Cohort Studies

    Science.gov (United States)

    Koizumi, Hideaki

    2011-01-01

    This article describes a number of human cohort studies based on the concept of brain-science and education. These studies assess the potential effects of new technologies on babies, children and adolescents, and test hypotheses drawn from animal and genetic case studies to see if they apply to people. A flood of information, virtual media,…

  9. Imaging Study Confirms Brain Differences in People with ADHD

    Science.gov (United States)

    ... Imaging Study Confirms Brain Differences in People With ADHD Attention-deficit/hyperactivity should be considered a brain ... Researchers who pinpointed brain differences in people with attention-deficit/hyperactivity disorder (ADHD) say their findings show the condition should ...

  10. In vivo Dynamic Studies of Brain Metabolism

    Institute of Scientific and Technical Information of China (English)

    LUO Xuechun; JIANG Yufeng; ZHANG Riqing

    2005-01-01

    Nuclear magnetic resonance (NMR) can noninvasively monitor intracellular concentrations and kinetic properties of numerous inorganic and organic compounds. A 31P NMR surface coil was used in vivo to dynamically measure phosphocreatine (PCr), adenosine triphosphate (ATP), and intracellular inorganic phosphate (Pi) levels in mouse brain during ischemia-reperfusion to study the damage of cerebral tissues caused by ischemia and effects of herbs on cerebral energy metabolism during ischemia-reperfusion. The study provides dynamic brain energy metabolism data during different periods. The data show that some herbs more rapidly increase the PCr level during the recovery phase than in the control group.

  11. Longitudinal MRI studies of brain morphometry

    DEFF Research Database (Denmark)

    Skimminge, Arnold Jesper Møller

    into the accompanying deformation field. Deformation fields from high dimensional warping founds tensor based morphometry (TBM), and provides unique opportunities to study human brain morphology and plasticity. In this thesis, specially adapted image processing streams utilizing several image registration techniques......High resolution MR images acquired at multiple time points of the brain allow quantification of localized changes induced by external factors such as maturation, ageing or disease progression/recovery. High-dimensional warping of such MR images incorporates changes induced by external factors...

  12. Studies of aluminum in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

    1985-01-01

    The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

  13. Zika Virus Can Damage Fetal Brain Late in Pregnancy: Study

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_161451.html Zika Virus Can Damage Fetal Brain Late in Pregnancy: Study ... WEDNESDAY, Oct. 12, 2016 (HealthDay News) -- The Zika virus may harm a baby's brain even if the ...

  14. Changes in HSP gene and protein expression in natural scrapie with brain damage

    Directory of Open Access Journals (Sweden)

    Serrano Carmen

    2011-01-01

    Full Text Available Abstract Heat shock proteins (Hsp perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease.

  15. Traumatic Brain Injury (TBI) Studies at Grady Memorial Hospital

    Science.gov (United States)

    2010-09-01

    management of adult, blunt-mechanism traumatic brain injury ( TBI ) patients and assess the overall mortality of this cohort at Grady...this study is to determine the current compliance with widely accepted guidelines for the management of severe traumatic brain injury ( TBI ) patients...AD_________________ Award Number: W81XWH-09-2-0145 Study Title: Traumatic Brain Injury ( TBI

  16. How do brain tumors alter functional connectivity? : A magnetoencephalography study

    NARCIS (Netherlands)

    Bartolomei, Fabrice; Bosma, Ingeborg; Klein, Martin; Baayen, Johannes C; Reijneveld, Jaap C; Postma, Tjeerd J; Heimans, Jan J; van Dijk, Bob W; de Munck, Jan C; de Jongh, Arent; Cover, Keith S; Stam, Cornelis J

    2006-01-01

    OBJECTIVE: This study was undertaken to test the hypothesis that brain tumors interfere with normal brain function by disrupting functional connectivity of brain networks. METHODS: Functional connectivity was assessed by computing the synchronization likelihood in a broad band (0.5-60Hz) or in the g

  17. Can Taichi reshape the brain? A brain morphometry study.

    Directory of Open Access Journals (Sweden)

    Gao-Xia Wei

    Full Text Available Although research has provided abundant evidence for Taichi-induced improvements in psychological and physiological well-being, little is known about possible links to brain structure of Taichi practice. Using high-resolution MRI of 22 Tai Chi Chuan (TCC practitioners and 18 controls matched for age, sex and education, we set out to examine the underlying anatomical correlates of long-term Taichi practice at two different levels of regional specificity. For this purpose, parcel-wise and vertex-wise analyses were employed to quantify the difference between TCC practitioners and the controls based on cortical surface reconstruction. We also adopted the Attention Network Test (ANT to explore the effect of TCC on executive control. TCC practitioners, compared with controls, showed significantly thicker cortex in precentral gyrus, insula sulcus and middle frontal sulcus in the right hemisphere and superior temporal gyrus and medial occipito-temporal sulcus and lingual sulcus in the left hemisphere. Moreover, we found that thicker cortex in left medial occipito-temporal sulcus and lingual sulcus was associated with greater intensity of TCC practice. These findings indicate that long-term TCC practice could induce regional structural change and also suggest TCC might share similar patterns of neural correlates with meditation and aerobic exercise.

  18. Infrared Imaging System for Studying Brain Function

    Science.gov (United States)

    Mintz, Frederick; Mintz, Frederick; Gunapala, Sarath

    2007-01-01

    A proposed special-purpose infrared imaging system would be a compact, portable, less-expensive alternative to functional magnetic resonance imaging (fMRI) systems heretofore used to study brain function. Whereas a typical fMRI system fills a large room, and must be magnetically isolated, this system would fit into a bicycle helmet. The system would include an assembly that would be mounted inside the padding in a modified bicycle helmet or other suitable headgear. The assembly would include newly designed infrared photodetectors and data-acquisition circuits on integrated-circuit chips on low-thermal-conductivity supports in evacuated housings (see figure) arranged in multiple rows and columns that would define image coordinates. Each housing would be spring-loaded against the wearer s head. The chips would be cooled by a small Stirling Engine mounted contiguous to, but thermally isolated from, the portions of the assembly in thermal contact with the wearer s head. Flexible wires or cables for transmitting data from the aforementioned chips would be routed to an integrated, multichannel transmitter and thence through the top of the assembly to a patch antenna on the outside of the helmet. The multiple streams of data from the infrared-detector chips would be sent to a remote site, where they would be processed, by software, into a three-dimensional display of evoked potentials that would represent firing neuronal bundles and thereby indicate locations of neuronal activity associated with mental or physical activity. The 3D images will be analogous to current fMRI images. The data would also be made available, in real-time, for comparison with data in local or internationally accessible relational databases that already exist in universities and research centers. Hence, this system could be used in research on, and for the diagnosis of response from the wearer s brain to physiological, psychological, and environmental changes in real time. The images would also be

  19. Functional brain imaging studies on specificity of meridian and acupoints

    Institute of Scientific and Technical Information of China (English)

    Xuezhi Li; Xuguang Liu; Fanrong Liang

    2008-01-01

    At present,the specificity of meridians and acupoints has been studied using functional brain imaging techniques from many standpoints.including meridians,acupoints,and sham acupoints,as well as different meridians and acupoints,coordination of acupoints,and factors influencing meridian and acupoint specificity.Preliminary experimental data have demonstrated that acupuncture at meridians and acupoints is specific with regard to brain neural information.However,research findings are contradictory,which may be related to brain functional complexity,resolution of functional brain imaging techniques,and experimental design.Future studies should further improve study method,and should strictly control experimental conditions to better analyze experimental data and acquire more beneficial data.Because of its many advantages.the functional brain imaging technique is a promising method for studying meridian and acupoint specificity.

  20. Genomic studies of mood disorders - the brain as a muscle?

    OpenAIRE

    Niculescu, Alexander B.

    2005-01-01

    Recent genomic studies showing abnormalities in the fibroblast growth factor system in the postmortem brains of people with major depressive disorder support previous indications of a role for growth factors in mood disorders. Similar molecular pathways, volumetric changes, and the effects of exercise on mood suggest a superficial analogy, and perhaps a deeper relationship, between muscle and brain functioning.

  1. Accelerated Brain Aging in Schizophrenia : A Longitudinal Pattern Recognition Study

    NARCIS (Netherlands)

    Schnack, Hugo G; van Haren, Neeltje E M; Nieuwenhuis, Mireille; Hulshoff Pol, Hilleke E; Cahn, Wiepke; Kahn, René S

    2016-01-01

    OBJECTIVE: Despite the multitude of longitudinal neuroimaging studies that have been published, a basic question on the progressive brain loss in schizophrenia remains unaddressed: Does it reflect accelerated aging of the brain, or is it caused by a fundamentally different process? The authors used

  2. Accelerated brain aging in schizophrenia : A longitudinal pattern recognition study

    NARCIS (Netherlands)

    Schnack, Hugo G.; Van Haren, Neeltje E M; Nieuwenhuis, Mireille; Pol, Hilleke E Hulshoff; Cahn, Wiepke; Kahn, René S.

    2016-01-01

    OBJECTIVE: Despite the multitude of longitudinal neuroimaging studies that have been published, a basic question on the progressive brain loss in schizophrenia remains unaddressed: Does it reflect accelerated aging of the brain, or is it caused by a fundamentally different process? The authors used

  3. Brain Imaging Studies of Developmental Stuttering.

    Science.gov (United States)

    Ingham, Roger J.

    2001-01-01

    A review of research on brain imaging of developmental stuttering concludes that findings increasingly point to a failure of normal temporal lobe activation during speech that may either contribute to (or is the result of) a breakdown in the sequencing of processing among premotor regions implicated in phonologic planning. (Contains references.)…

  4. Using autopsy brain tissue to study alcohol-related brain damage in the genomic age

    OpenAIRE

    Sutherland, Greg T.; Sheedy, Donna; Kril, Jillian J.

    2013-01-01

    The New South Wales Tissue Resource Centre (NSW TRC) at the University of Sydney, Australia is one of the few human brain banks dedicated to the study of the effects of chronic alcoholism. The bank was affiliated in 1994 as a member of the National Network of Brain Banks and also focuses on schizophrenia and healthy control tissue. Alcohol abuse is a major problem worldwide, manifesting in such conditions as fetal alcohol syndrome, adolescent binge drinking, alcohol dependency and alcoholic n...

  5. Study Links Stuttering to Less Blood Flow in Brain

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_162922.html Study Links Stuttering to Less Blood Flow in Brain The more ... to speech may put people at risk for stuttering, a small study suggests. There are also signs ...

  6. A multichannel time-domain brain oximeter for clinical studies

    Science.gov (United States)

    Contini, Davide; Spinelli, Lorenzo; Caffini, Matteo; Cubeddu, Rinaldo; Torricelli, Alessandro

    2009-07-01

    We developed and optimized a multichannel dual-wavelength time-domain brain oximeter for functional studies in the clinical environment. The system, mounted on a 19"-rack, is interfaced with instrumentation for monitoring physiological parameters and for stimuli presentation.

  7. A prospective study to evaluate a new residential community reintegration programme for severe chronic brain injury: the Brain Integration Programme.

    NARCIS (Netherlands)

    Geurtsen, G.J.; Martina, J.D.; Heugten, C.M. van; Geurts, A.C.H.

    2008-01-01

    PURPOSE: To assess the effectiveness of a residential community reintegration programme for participants with chronic sequelae of severe acquired brain injury that hamper community functioning. DESIGN: Prospective cohort study. SUBJECTS: Twenty-four participants with acquired brain injury (traumatic

  8. Vocal Emotion of Humanoid Robots: A Study from Brain Mechanism

    Directory of Open Access Journals (Sweden)

    Youhui Wang

    2014-01-01

    Full Text Available Driven by rapid ongoing advances in humanoid robot, increasing attention has been shifted into the issue of emotion intelligence of AI robots to facilitate the communication between man-machines and human beings, especially for the vocal emotion in interactive system of future humanoid robots. This paper explored the brain mechanism of vocal emotion by studying previous researches and developed an experiment to observe the brain response by fMRI, to analyze vocal emotion of human beings. Findings in this paper provided a new approach to design and evaluate the vocal emotion of humanoid robots based on brain mechanism of human beings.

  9. Wearable sensor network to study laterality of brain functions.

    Science.gov (United States)

    Postolache, Gabriela B; Girao, Pedro S; Postolache, Octavian A

    2015-08-01

    In the last decade researches on laterality of brain functions have been reinvigorated. New models of lateralization of brain functions were proposed and new methods for understanding mechanisms of asymmetry between right and left brain functions were described. We design a system to study laterality of motor and autonomic nervous system based on wearable sensors network. A mobile application was developed for analysis of upper and lower limbs movements, cardiac and respiratory function. The functionalities and experience gained with deployment of the system are described.

  10. Using autopsy brain tissue to study alcohol-related brain damage in the genomic age.

    Science.gov (United States)

    Sutherland, Greg T; Sheedy, Donna; Kril, Jillian J

    2014-01-01

    The New South Wales Tissue Resource Centre at the University of Sydney, Australia, is one of the few human brain banks dedicated to the study of the effects of chronic alcoholism. The bank was affiliated in 1994 as a member of the National Network of Brain Banks and also focuses on schizophrenia and healthy control tissue. Alcohol abuse is a major problem worldwide, manifesting in such conditions as fetal alcohol syndrome, adolescent binge drinking, alcohol dependency, and alcoholic neurodegeneration. The latter is also referred to as alcohol-related brain damage (ARBD). The study of postmortem brain tissue is ideally suited to determining the effects of long-term alcohol abuse, but it also makes an important contribution to understanding pathogenesis across the spectrum of alcohol misuse disorders and potentially other neurodegenerative diseases. Tissue from the bank has contributed to 330 peer-reviewed journal articles including 120 related to alcohol research. Using the results of these articles, this review chronicles advances in alcohol-related brain research since 2003, the so-called genomic age. In particular, it concentrates on transcriptomic approaches to the pathogenesis of ARBD and builds on earlier reviews of structural changes (Harper et al. Prog Neuropsychopharmacol Biol Psychiatry 2003;27:951) and proteomics (Matsumoto et al. Expert Rev Proteomics 2007;4:539).

  11. Sleep Deprivation Makes the Young Brain Resemble the Elderly Brain: A Large-Scale Brain Networks Study.

    Science.gov (United States)

    Zhou, Xinqi; Wu, Taoyu; Yu, Jing; Lei, Xu

    2017-02-01

    Decreased cognition performance and impaired brain function are similar results of sleep deprivation (SD) and aging, according to mounted supporting evidence. Some investigators even proposed SD as a model of aging. However, few direct comparisons were ever explored between the effects of SD and aging by network module analysis with the resting-state functional magnetic resonance imaging. In this study, both within-module and between-module (BT) connectivities were calculated in the whole brain to describe a complete picture of brain networks' functional connectivity among three groups (young normal sleep, young SD, and old group). The results showed that the BT connectivities in subcortical and cerebellar networks were significantly declined in both the young SD group and old group. There were six other networks, that is, ventral attention, dorsal attention, default mode, auditory, cingulo-opercular, and memory retrieval networks, significantly influenced by aging. Therefore, we speculated that the effects of SD on the young group can be regarded as a simplified model of aging. Moreover, this provided a possible explanation, that is, the old were more tolerable for SD than the young. However, SD may not be a considerable model for aging when discussing the brain regions related to those SD-uninfluenced networks.

  12. A Self-Study Tutorial using the Allen Brain Explorer and Brain Atlas to Teach Concepts of Mammalian Neuroanatomy and Brain Function.

    Science.gov (United States)

    Jenks, Bruce G

    2009-01-01

    The Allen Brain Atlas is a repository of neuroanatomical data concerning the mouse brain. The core of the database is a Nissl-stained reference atlas of the brain accompanied by in situ hybridization data for essentially the entire mouse genome. This database is freely available at the Allen Institute for Brain Science website, as is an innovative tool to explore the database, the Brain Explorer. This tool is downloaded and installed on your own computer. I have developed a self-study tutorial, "Explorations with the Allen Brain Explorer", which uses the Brain Explorer and the Brain Atlas to teach fundamentals of mammalian neuroanatomy and brain function. In this tutorial background information and step-by-step exercises on the use of the Brain Explorer are given using PowerPoint as a platform. To do the tutorial both the PowerPoint and the Brain Explorer are opened on the computer and the students switch from one program to the other as they go, in a step-wise fashion, through the various exercises. There are two main groups of exercises, titled "The Basics" and "Explorations", with both groups accessed from a PowerPoint "Start Menu" by clicking on dynamic links to the appropriate exercises. Most exercises have a number of dynamic links to PowerPoint slides where background information for the exercises is given or the neuroanatomical data collected from the Brain Atlas is discussed.

  13. Brain connectivity study of brain tumor patients using MR-PET data: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Ana Carina [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon (Portugal); Ribeiro, Andre Santos [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon (Portugal); Centre for Neuropsychopharmacology, Division of Brain Sciences, Department of Medicine, Imperial College London, London (United Kingdom); Oros-Peusquens, Ana Maria; Langen, Karl Josef; Shah, Jon [Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich (Germany); Ferreira, Hugo Alexandre [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon (Portugal)

    2015-05-18

    Brain activity results from anatomical and functional connections that can be disrupted or altered due to trauma or lesion. This work presents a first approach on the study of whole-brain connectivity of brain tumor patients using the Multimodal Imaging Brain Connectivity (MIBCA) toolbox. Two patients with glioblastoma lesions located in the left hemisphere (one in the motor cortex and the other in the temporal lobe) underwent simultaneous MRI and dynamic PET scans using a 3T MRI scanner with a BrainPET insert. The following data was acquired: T1-w MPRAGE (1x1x1mm{sup 3}), DTI (dir=30, b=0,800s/mm2, 2x2x2mm{sup 3}), and dynamic 18F-FET PET. The MIBCA toolbox was used to automatically pre-process MRI-PET data and to derive imaging and connectivity metrics from the multimodal data. Computed metrics included: cortical thickness from T1-w data; mean diffusivity (MD), fractional anisotropy (FA), node degree, clustering coefficient and pairwise ROI fibre tracking (structural connectivity) from DTI data; and standardized uptake value (SUV) from PET data. For all the metrics, the differences between left and right hemispherical structures were obtained, followed by a 25% threshold (except for SUV thresholded at 15%). Data was visualized in a connectogram, and both structural connectivity and metrics were studied in regions surrounding lesions. Preliminary results showed increased SUV values in regions surrounding the tumor for both patients. Patients also showed changes in structural connectivity involving these regions and also other more spatially distant regions such as the putamen and the pallidum, including decreased number of fibers between the subcortical structures themselves and with frontal regions. These findings suggest that the presence of a tumor may alter both local and more distant structural connections. Presently, a larger patient sample is being studied along with the inclusion of a control group to test the consistency of the findings.

  14. Brain-computer interfacing under distraction: an evaluation study

    DEFF Research Database (Denmark)

    Brandl, Stephanie; Frølich, Laura; Höhne, Johannes;

    2016-01-01

    Objective. While motor-imagery based brain-computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach...

  15. Study Reveals Brain Biology behind Self-Control

    Science.gov (United States)

    Sparks, Sarah D.

    2011-01-01

    A new neuroscience twist on a classic psychology study offers some clues to what makes one student able to buckle down for hours of homework before a test while his classmates party. The study published in the September 2011 edition of "Proceedings of the National Academy of Science," suggests environmental cues may "hijack" the brain's mechanisms…

  16. A CASE STUDY OF BRAIN VOLUME REDUCTION IN MULTIPLE SCLEROSIS

    Directory of Open Access Journals (Sweden)

    Ivan N. Dimitrov

    2013-07-01

    Full Text Available The development of sophisticated magnetic resonance imaging techniques and software for medical imaging processing and analysis has led to a significant progress in multiple sclerosis research and clinical care. The measurement of brain volumes provides a quantitative representation of damage, thus facilitating the objective follow-up process. The parameters obtained, though not being used routinely in clinical practice, are more and more often applied in clinical studies. The amount of whole brain and regional atrophy, estimated from serial scans, is considered important not only for disease progression, but also for cognitive dysfunction which is common in multiple sclerosis. In this paper we describe a volumetric study of two magnetic resonance scans of a patient with relapsing-remitting multiple sclerosis, performed 16 months one after the other, and analyzed using FSL SIENA software. Analysis demonstrated brain volume reduction of 1.7% between the two scans. We discuss the advantages of the method and its possible clinical applications.

  17. MR Connectomics: A Conceptual Framework for Studying The Developing Brain

    Directory of Open Access Journals (Sweden)

    Patric eHagmann

    2012-06-01

    Full Text Available The combination of advanced neuroimaging techniques and major developments in complex network science, have given birth to a new framework for studying the brain: connectomics. This framework provides the ability to describe and study the brain as a dynamic network and to explore how the coordination and integration of information processing may occur. In recent years this framework has been used to investigate the developing brain and has shed light on many dynamic changes occurring from infancy through adulthood. The aim of this article is to review this work and to discuss what we have learned from it. We will also use this body of work to highlight key technical aspects that are necessary in general for successful connectome analysis using today’s advanced neuroimaging techniques. We look to identify current limitations of such approaches, what can be improved, and how these points generalize to other topics in connectome research.

  18. Fourier-wavelet restoration in PET/CT brain studies

    Energy Technology Data Exchange (ETDEWEB)

    Knesaurek, Karin, E-mail: karin.knesaurek@mssm.edu [Division of Nuclear Medicine, The Mount Sinai Medical Center, One Gustave L. Levy Place, New York, NY 10029 (United States)

    2012-10-11

    Our goal is to improve brain PET imaging through the application of a novel, hybrid Fourier-wavelet (WFT) restoration technique. The major limitation of PET studies is a relatively poor resolution in comparison with MRI and CT imaging and there is a need for improved PET imaging. A GE DLS PET/CT 16 slice system was used to acquire the studies. In order to create restoration filters the point source study was performed. The 6-fillable spheres and 3D Hoffman brain phantom studies were acquired and used to test and optimize the restoration approach. The patient data used in the study were acquired in a 3D PET mode, using the standard clinical protocol. Here, we have implemented Fourier-wavelet regularized restoration. In the Fourier domain, the inverse of modulation transfer function was multiplied by a Butterworth low-pass filter, order n=6 and cut-off frequency f=0.35 cycles/pixel. In addition, wavelet (Daubechies, order 2) noise suppression was applied by 'hard threshold'. Hot spheres and 3D Hoffman brain studies showed that the restoration process not only improves resolution and contrast but also improves quantification in 3D PET/CT imaging. The average contrast increase was 19% and the quantification improved in the range 8-20% depending on sphere size. In the restored images, there was no significant increase in noise when compared with the original images. The clinical studies followed brain phantom findings, i.e., the restored images had better contrast and resolution properties, when compared with the original images. The results of the study demonstrate that the quality and quantification of 3D brain {sup 18}F FDG PET images can be significantly improved by Fourier-wavelet (WFT) restoration filtering.

  19. DSC Study on Brain Tubulin and the Effect of Cisplatin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The thermal property of the polymerization of brain tubulin was studied by a high-sensitivity differential scanning calorimeter. The phenomenon that heat flows increased and decreased consistently and obviously was observed. This phenomenon was called heat flow oscillation. It was probably correlated to the dynamic instability of microtubules. The effect of cisplatin on it was reported, too.

  20. The effect of chemotherapy on rat brain PET: preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Kim, Il Han; Yu, A Ram; Park, Ji Ae; Woo, Sang Keun; Kim, Jong Guk; Cheon, Gi Jeong; Kim, Byeong Il; Choi, Chang Woon; Lim, Sang Moo; Kim, Hee Joung; Kim, Kyeong Min [Korea Institute Radiological and Medical Science, Seoul (Korea, Republic of)

    2010-10-15

    Chemotherapy was widely used for the therapy of cancer patients. When chemotherapy was performed, transient cognitive memory problem was occurred. This cognitive problem in brain was called as chemobrain. In this study, we have developed rat model for chemobrain. Cerebral glucose metabolism after chemotherapy was assessed using animal PET and voxel based statistical analysis method

  1. Functional brain imaging studies of youth depression: A systematic review

    Directory of Open Access Journals (Sweden)

    Rebecca Kerestes

    2014-01-01

    Conclusions: Youth MDD is characterized by abnormal activations in ventromedial frontal regions, the anterior cingulate and amygdala, which are broadly consistent with the implicated role of medial network regions in the pathophysiology of depression. Future longitudinal studies examining the effects of neurodevelopmental changes and pubertal maturation on brain systems implicated in youth MDD will provide a more comprehensive neurobiological model of youth depression.

  2. Does studying abroad induce a brain drain?

    NARCIS (Netherlands)

    H. Oosterbeek; D. Webbink

    2011-01-01

    This paper investigates whether studying abroad increases the propensity to live abroad later on. We use an instrumental variable approach based on cut-offs in the ranking of Dutch higher education graduates who applied for a scholarship programme for outstanding students. Applicants ranked above th

  3. Studies of the brain cannabinoid system using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S.J.; Volkow, N.D.

    1995-10-01

    Studies using radiolabeled psychoactive drugs in conjunction with positron emission tomography (PET) have permitted the imaging of binding sites in the human brain. Similar studies of marijuana have been hampered by the unsuitability of radiolabeled THC for PET studies, and the current unavailability of other in vivo imaging agents for cannabinoid receptors. Recent developments in medicinal chemistry suggest that a PET radiotracer for cannabinoid receptors will soon become available. This chapter briefly reviews these developments, together with the results of PET studies of the effects of marijuana and other abused drugs on brain metabolism. It also reviews PET studies of cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available.

  4. Noninvasive measurement of brain glycogen by nuclear magnetic resonance spectroscopy and its application to the study of brain metabolism.

    Science.gov (United States)

    Tesfaye, Nolawit; Seaquist, Elizabeth R; Oz, Gülin

    2011-12-01

    Glycogen is the reservoir for glucose in the brain. Beyond the general agreement that glycogen serves as an energy source in the central nervous system, its exact role in brain energy metabolism has yet to be elucidated. Experiments performed in cell and tissue culture and animals have shown that glycogen content is affected by several factors, including glucose, insulin, neurotransmitters, and neuronal activation. The study of in vivo glycogen metabolism has been hindered by the inability to measure glycogen noninvasively, but, in the past several years, the development of a noninvasive localized (13) C nuclear magnetic resonance (NMR) spectroscopy method has allowed the study of glycogen metabolism in the conscious human. With this technique, (13) C-glucose is administered intravenously, and its incorporation into and washout from brain glycogen is tracked. One application of this method has been to the study of brain glycogen metabolism in humans during hypoglycemia: data have shown that mobilization of brain glycogen is augmented during hypoglycemia, and, after a single episode of hypoglycemia, glycogen synthesis rate is increased, suggesting that glycogen stores rebound to levels greater than baseline. Such studies suggest that glycogen may serve as a potential energy reservoir in hypoglycemia and may participate in the brain's adaptation to recurrent hypoglycemia and eventual development of hypoglycemia unawareness. Beyond this focused area of study, (13) C NMR spectroscopy has a broad potential for application in the study of brain glycogen metabolism and carries the promise of a better understanding of the role of brain glycogen in diabetes and other conditions.

  5. Connecting Brain Research to Classroom Learning: A Mixed-Method Study on How Teachers Apply Brain Research to Their Instruction

    Science.gov (United States)

    McAteer, Todd C.

    2010-01-01

    Purpose. The purpose of this study was to examine how knowledgeable teachers are in utilizing brain-researched instructional strategies. The research focused on determining which brain-researched strategies are implemented, the accuracy with which they are employed, and the degree to which they are utilized. A literature review revealed the most…

  6. Brain SCALE : Brain Structure and Cognition: an Adolescent Longitudinal Twin Study into the Genetic Etiology of Individual Differences

    NARCIS (Netherlands)

    van Soelen, Inge L. C.; Brouwer, Rachel M.; Peper, Jiska S.; van Leeuwen, Marieke; Koenis, Marinka M. G.; van Beijsterveldt, Toos C. E. M.; Swagerman, Suzanne C.; Kahn, Rene S.; Pol, Hilleke E. Hulshoff; Boomsma, Dorret I.

    2012-01-01

    From childhood into adolescence, the child's brain undergoes considerable changes in both structure and function. Twin studies are of great value to explore to what extent genetic and environmental factors explain individual differences in brain development and cognition. In The Netherlands, we init

  7. Abnormal brain processing of pain in migraine without aura: a high-density EEG brain mapping study

    DEFF Research Database (Denmark)

    Egsgaard, L L; Jensen, R; Buchgreitz, L

    2010-01-01

    In the present study we used high-density EEG brain mapping to investigate spatio-temporal aspects of brain activity in response to experimentally induced muscle pain in 17 patients with migraine without aura and 15 healthy controls. Painful electrical stimuli were applied to the trapezius muscle...... to the tonic muscle pain condition (z = 29 mm vs. z =¿-13 mm, P aura....

  8. New perspectives on using brain imaging to study CNS stimulants.

    Science.gov (United States)

    Lukas, Scott E

    2014-12-01

    While the recent application of brain imaging to study CNS stimulants has offered new insights into the fundamental factors that contribute to their use and abuse, many gaps remain. Brain circuits that mediate pleasure, dependence, craving and relapse are anatomically, neurophysiologically and neurochemically distinct from one another, which has guided the search for correlates of stimulant-seeking and taking behavior. However, unlike other drugs of abuse, metrics for tolerance and physical dependence on stimulants are not obvious. The dopamine theory of stimulant abuse does not sufficiently explain this disorder as serotonergic, GABAergic and glutamagergic circuits are clearly involved in stimulant pharmacology and so tracking the source of the "addictive" processes must adopt a more multimodal, multidisciplinary approach. To this end, both anatomical and functional magnetic resonance imaging (MRI), MR spectroscopy (MRS) and positron emission tomography (PET) are complementary and have equally contributed to our understanding of how stimulants affect the brain and behavior. New vistas in this area include nanotechnology approaches to deliver small molecules to receptors and use MRI to resolve receptor dynamics. Anatomical and blood flow imaging has yielded data showing that cognitive enhancers might be useful adjuncts in treating CNS stimulant dependence, while MRS has opened opportunities to examine the brain's readiness to accept treatment as GABA tone normalizes after detoxification. A desired outcome of the above approaches is being able to offer evidence-based rationales for treatment approaches that can be implemented in a more broad geographic area, where access to brain imaging facilities may be limited. This article is part of the Special Issue entitled 'CNS Stimulants'.

  9. Boosting bioluminescence neuroimaging: an optimized protocol for brain studies.

    Science.gov (United States)

    Aswendt, Markus; Adamczak, Joanna; Couillard-Despres, Sebastien; Hoehn, Mathias

    2013-01-01

    Bioluminescence imaging is widely used for optical cell tracking approaches. However, reliable and quantitative bioluminescence of transplanted cells in the brain is highly challenging. In this study we established a new bioluminescence imaging protocol dedicated for neuroimaging, which increases sensitivity especially for noninvasive tracking of brain cell grafts. Different D-Luciferin concentrations (15, 150, 300 and 750 mg/kg), injection routes (i.v., i.p., s.c.), types of anesthesia (Isoflurane, Ketamine/Xylazine, Pentobarbital) and timing of injection were compared using DCX-Luc transgenic mice for brain specific bioluminescence. Luciferase kinetics was quantitatively evaluated for maximal photon emission, total photon emission and time-to-peak. Photon emission followed a D-Luciferin dose-dependent relation without saturation, but with delay in time-to-peak increasing for increasing concentrations. The comparison of intravenous, subcutaneous and intraperitoneal substrate injection reflects expected pharmacokinetics with fastest and highest photon emission for intravenous administration. Ketamine/Xylazine and Pentobarbital anesthesia showed no significant beneficial effect on maximal photon emission. However, a strong difference in outcome was observed by injecting the substrate pre Isoflurane anesthesia. This protocol optimization for brain specific bioluminescence imaging comprises injection of 300 mg/kg D-Luciferin pre Isoflurane anesthesia as an efficient and stable method with a signal gain of approx. 200% (compared to 150 mg/kg post Isoflurane). Gain in sensitivity by the novel imaging protocol was quantitatively assessed by signal-to-noise calculations of luciferase-expressing neural stem cells grafted into mouse brains (transplantation of 3,000-300,000 cells). The optimized imaging protocol lowered the detection limit from 6,000 to 3,000 cells by a gain in signal-to-noise ratio.

  10. Increased brain iron deposition is a risk factor for brain atrophy in patients with haemodialysis: a combined study of quantitative susceptibility mapping and whole brain volume analysis.

    Science.gov (United States)

    Chai, Chao; Zhang, Mengjie; Long, Miaomiao; Chu, Zhiqiang; Wang, Tong; Wang, Lijun; Guo, Yu; Yan, Shuo; Haacke, E Mark; Shen, Wen; Xia, Shuang

    2015-08-01

    To explore the correlation between increased brain iron deposition and brain atrophy in patients with haemodialysis and their correlation with clinical biomarkers and neuropsychological test. Forty two patients with haemodialysis and forty one age- and gender-matched healthy controls were recruited in this prospective study. 3D whole brain high resolution T1WI and susceptibility weighted imaging were scanned on a 3 T MRI system. The brain volume was analyzed using voxel-based morphometry (VBM) in patients and to compare with that of healthy controls. Quantitative susceptibility mapping was used to measure and compare the susceptibility of different structures between patients and healthy controls. Correlation analysis was used to investigate the relationship between the brain volume, iron deposition and neuropsychological scores. Stepwise multiple regression analysis was used to explore the effect of clinical biomarkers on the brain volumes in patients. Compared with healthy controls, patients with haemodialysis showed decreased volume of bilateral putamen and left insular lobe (All P putamen, substantia nigra, red nucleus and dentate nucleus were significantly higher (All P putamen (P putamen (P < 0.05). Our study indicated increased brain iron deposition and dialysis duration was risk factors for brain atrophy in patients with haemodialysis. The decreased gray matter volume of the left insular lobe was correlated with neurocognitive impairment.

  11. STUDY OF BRAIN TUMOURS BY NOVE L MAGNETIC RESONANCE TECHNIQUE

    OpenAIRE

    Mohammad Shamim; Reyaz; Anju; Dinesh Kumar; Paricharak

    2015-01-01

    In the present study , thirty patients in the age range of 22 to 63 years of age were included after being diagnosed to be having brain tumour on CT scan or conventional MRI. In addition DWI , MRS , and PWI were carried out i n these patients. All the patients with suspicious malignant lesions were then subjected to FDG - PET examination . Histopathological correlation was obtained in all the patients to serve as gold standard against which other m...

  12. Adapting Parcellation Schemes to Study Fetal Brain Connectivity in Serial Imaging Studies

    DEFF Research Database (Denmark)

    Cheng, Xi; Wilm, Jakob; Seshamani, Sharmishtaa

    2013-01-01

    of the developing fetal brain such functional and associated structural markers are not consistently present over time. In this study we adapt two non-atlas based parcellation schemes to study the development of connectivity networks of a fetal monkey brain using Diffusion Weighted Imaging techniques. Results......A crucial step in studying brain connectivity is the definition of the Regions Of Interest (ROI's) which are considered as nodes of a network graph. These ROI's identified in structural imaging reflect consistent functional regions in the anatomies being compared. However in serial studies...

  13. Suicide after traumatic brain injury: a population study

    DEFF Research Database (Denmark)

    Teasdale, T W; Engberg, A W

    2001-01-01

    OBJECTIVES: To determine the rates of suicide among patients who have had a traumatic brain injury. METHODS: From a Danish population register of admissions to hospital covering the years 1979-93 patients were selected who had had either a concussion (n=126 114), a cranial fracture (n=7560......), or a cerebral contusion or traumatic intracranial haemorrhage (n=11 766). All cases of deaths by the end of the study period were identified. RESULTS: In the three diagnostic groups there had been 750 (0.59%), 46 (0.61%), and 99 (0.84%) cases of suicide respectively. Standardised mortality ratios, stratified......). There was, however, no evidence of a specific risk period for suicide after injury. CONCLUSION: The increased risk of suicide among patients who had a mild traumatic brain injury may result from concomitant risk factors such as psychiatric conditions and psychosocial disadvantage. The greater risk among...

  14. Sulforaphane inhibits pancreatic cancer through disrupting Hsp90-p50Cdc37complex and direct interactions with amino acids residues of Hsp90

    NARCIS (Netherlands)

    Li, Yanyan; Karagöz, G. Elif; Seo, Young Ho; Zhang, Tao; Jiang, Yiqun; Yu, Yanke; Duarte, Afonso M.S.; Schwartz, Steven J.; Boelens, Rolf; Carroll, Kate; Rüdiger, Stefan G.D.; Sun, Duxin

    2012-01-01

    Sulforaphane [1-isothiocyanato-4-(methyl-sulfinyl) butane)], an isothiocyanate derived from cruciferous vegetables, has been shown to possess potent chemopreventive activity. We analyzed the effect of sulforaphane on the proliferation of pancreatic cancer cells. Sulforaphane inhibited pancreatic can

  15. Clinicopathological pattern of brain tumors: A 3-year study in a tertiary care hospital in India

    OpenAIRE

    Sajeeb Mondal; Rajashree Pradhan; Subrata Pal; Biswajit Biswas; Arindam Banerjee; Debosmita Bhattacharyya

    2016-01-01

    Background: Brain tumors are heterogeneous group of neoplasms, affecting different age groups. Although some studies have been published regarding pathological pattern of brain tumors from different countries of the world and also from India, comprehensive clinicopathological studies from Eastern India is lacking. Aims: The aim of this study was to observe recent incidence of different brain tumors and to study clinical and histopathological spectrum of brain tumors in Eastern India. Material...

  16. Vitamins in the monkey brain: An immunocytochemical study.

    Science.gov (United States)

    Mangas, A; Coveñas, R; Bodet, D; Duleu, S; Marcos, P; Geffard, M

    2009-09-01

    Using highly specific antisera directed against vitamins, the distribution of pyridoxal-, pyridoxine-, vitamin C- and nicotinamide-immunoreactive structures in the monkey (Macaca fascicularis) brain was studied. Neither immunoreactive structures containing pyridoxine or nicotinamide, nor immunoreactive fibers containing vitamin C were found in the monkey brain. However, this work reports the first visualization and the morphological characteristics of pyridoxal- and vitamin C-immunoreactive cell bodies in the mammalian central nervous system using an indirect immunoperoxidase technique. A high density of pyridoxal-immunoreactive cell bodies was found in the paraventricular hypothalamic nucleus and in the supraoptic nucleus and a low density of the same was observed in the periventricular hypothalamic region, whereas a moderate density of vitamin C-immunoreactive cell bodies was observed in the somatosensorial cortex (precentral gyrus). Immunoreactive fibers containing pyridoxal were only visualized in the anterior commissure. The restricted distribution of pyridoxal and vitamin C in the monkey brain suggests that both vitamins could be involved in very specific physiological mechanisms.

  17. Brain potentials distinguish new and studied objects during working memory.

    Science.gov (United States)

    Guo, Chunyan; Lawson, Adam L; Zhang, Qin; Jiang, Yang

    2008-04-01

    We investigated brain responses to matching versus nonmatching objects in working memory (WM) with a modified delayed match-to-sample task using event-related potentials (ERPs). In addition, ERP correlates of new items (new matches/new nonmatches) and previously studied items (studied matches/studied nonmatches) were examined in the WM task. Half of the common visual objects were initially studied until 95% accuracy was attained and half were new. Each memory trial began with the presentation of a sample object followed by nine test objects. Participants indicated whether each test item was the same as the object held in mind (i.e., match) or a nonmatch. Compared to studied matches, new matches evoked activity that was 50 ms earlier and largest at frontal sites. In contrast, P3 activity associated with studied nonmatches was larger than for new nonmatches at mostly posterior sites, which parallels previously reported old-new ERP effects. The ERP source analysis further confirms that the cortical mechanisms underlying matching objects and rejecting irrelevant objects during the task are both temporally and spatially distinct. Moreover, our current findings suggest that prior learning affects brain responses to matching visual items during a WM task.

  18. The effects of Psychotropic drugs On Developing brain (ePOD) study : methods and design

    NARCIS (Netherlands)

    Bottelier, Marco A.; Schouw, Marieke L. J.; Klomp, Anne; Tamminga, Hyke G. H.; Schrantee, Anouk G. M.; Bouziane, Cheima; de Ruiter, Michiel B.; Boer, Frits; Ruhe, Henricus G.; Denys, Damiaan; Rijsman, Roselyne; Lindauer, Ramon J. L.; Reitsma, Hans B.; Geurts, Hilde M.; Reneman, Liesbeth

    2014-01-01

    Background: Animal studies have shown that methylphenidate (MPH) and fluoxetine (FLX) have different effects on dopaminergic and serotonergic system in the developing brain compared to the developed brain. The effects of Psychotropic drugs On the Developing brain (ePOD) study is a combination of dif

  19. Anticipatory Processing in the Brain on the Perception of Müller-Lyer Illusionary Figures—A Brain Potential Study

    Science.gov (United States)

    Nomura, Shusaku; Sasaki, Shuntaro; Hirakawa, Masato; Hiwaki, Osamu

    2010-11-01

    We investigated the brain potential in relation with the recognition of Müller-Lyer (ML) illusionary figure, which was a famous optical illusion. Although it is frequently assumed that the ML illusionary effect could be derived from its geometrical construction, it derives the same length miss-estimation effect on the sense of touch; haptic illusion. Moreover it occurs in people who are blindfolded or congenital blind. Thus somehow higher information processing than the optical one within the brain could be expected to involve with the recognition of ML figure while few brain studies have demonstrated it. We then investigated the brain waves under subjects' perceiving ML illusionary figure. As a result the marked difference of the brain potential between ML and the control condition around the midline of parietal brain, where the multi-modal perception information was thought to associate within the brain, was observed. This result implies that the anticipatory processing on the perception of ML illusionary figures would be derived by integrating multi-sensory information.

  20. A neurological comparative study of the harp seal (Pagophilus groenlandicus) and harbor porpoise (Phocoena phocoena) brain

    DEFF Research Database (Denmark)

    Walløe, Solveig; Eriksen, Nina; Dabelsteen, Torben

    2010-01-01

    The cetacean brain is well studied. However, few comparisons have been done with other marine mammals. In this study, we compared the harp seal (Pagophilus groenlandicus) and the harbor porpoise brain (Phocoena phocoena). Stereological methods were applied to compare three areas of interest...... are the first to provide estimates of the number of neurons and glial cells in the neocortex of the harp seal and harbor porpoise brain and offer new data to the comparative field of mammalian brain evolution....

  1. Brain shrinkage in chronic alcoholics: a pathological study.

    Science.gov (United States)

    Harper, C G; Kril, J J; Holloway, R L

    1985-02-16

    A quantitative neuropathological necropsy study of 22 control and 22 chronic alcoholic subjects showed a statistically significant loss of brain tissue in the chronic alcoholic group. The loss of tissue appeared to be from the white matter of the cerebral hemispheres rather than the cerebral cortex. This may reflect a primary alteration in the composition or structure of the white matter or it may be secondary to loss of nerve cells from the cortex with subsequent degeneration of the axons in the white matter. Further morphometric analyses including cortical neuronal counts will be necessary to clarify this issue.

  2. Study Suggests Brain Is Hard-Wired for Chronic Pain

    Science.gov (United States)

    ... the Apkarian laboratory showed that the volume of grey matter in the brains of the same subjects who had persistent pain decreased over the same year. Grey matter describes the area of the brain where the ...

  3. Aerobic Exercise Intervention, CognitivePerformance, and Brain Structure : results from the Physical Influences on Brain in Aging (PHIBRA) Study

    OpenAIRE

    Jonasson, Lars; Nyberg, Lars; Kramer, Arthur; Lundquist, Anders; Riklund, Katrine; Boraxbekk, Carl-Johan

    2017-01-01

    Studies have shown that aerobic exercise has the potential to improve cognition and reduce brain atrophy in older adults. However, the literature is equivocal with regards to the specificity or generality of these effects. To this end, we report results on cognitive function and brain structure from a 6-month training intervention with 60 sedentary adults (64–78 years) randomized to either aerobic training or stretching and toning control training. Cognitive functions were assessed with a neu...

  4. Endocasts-the direct evidence and recent advances in the study of human brain evolution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Brain evolution is one of the most important aspects of human evolution, usually studied through endocasts. Analysis of fossil hominid endocasts allows inferences on functional anatomy, physiology, and phylogeny. In this paper, we describe the general features of endocast studies and review some of the major topics in paleoneurology. These are: absolute and relative brain size evolution; brain shape variation; brain asymmetry and lateralization; middle meningeal vessels and venous sinuses; application of computed tomography and virtual imaging; the history of Chinese brain endocast studies. In particular, this review emphasizes endocast studies on Chinese hominin fossils.

  5. Memory Networks in Tinnitus: A Functional Brain Image Study

    Science.gov (United States)

    Laureano, Maura Regina; Onishi, Ektor Tsuneo; Bressan, Rodrigo Affonseca; Castiglioni, Mario Luiz Vieira; Batista, Ilza Rosa; Reis, Marilia Alves; Garcia, Michele Vargas; de Andrade, Adriana Neves; de Almeida, Roberta Ribeiro; Garrido, Griselda J.; Jackowski, Andrea Parolin

    2014-01-01

    Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT) to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls. Methods: Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT). The severity of tinnitus was assessed using the “Tinnitus Handicap Inventory” (THI). The images were processed and analyzed using “Statistical Parametric Mapping” (SPM8). Results: A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05) was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus. Conclusion: It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes. PMID:24516567

  6. Memory networks in tinnitus: a functional brain image study.

    Directory of Open Access Journals (Sweden)

    Maura Regina Laureano

    Full Text Available Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls.Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT. The severity of tinnitus was assessed using the "Tinnitus Handicap Inventory" (THI. The images were processed and analyzed using "Statistical Parametric Mapping" (SPM8.A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05 was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus.It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.

  7. STUDY ABOUT CLINICAL APPLICATION OF BRAIN ATLAS IN PAEDIATRICS

    Institute of Scientific and Technical Information of China (English)

    MENG Fanhang; LIU Cuiping; RENG Xiaoping; JIANG Lian

    2002-01-01

    Objectives To explore clinical application on brain atlas in paediatrics. Methode: Brain atlas was applied in diagnosis and treatment of paediatric diseases and its clinical value was discussed in 1990 ~2001. The manifestation of these diseases in brain atlas were analysed and the manifestation of CT of 67 cases and manifestations of EEG of 37 cases with that of BA were compared. Results The changes of cerebral electrical activity of these diseases were reflected objectively and showed directly in BA. Conclusion Brain atlas not only can point out quality of disease but also define position of disease. Therefore, brain atlas has important clinical value in paediatrics.

  8. The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I.; Stam, C.; Douw, L.; Bartolomei, F.; Heimans, J.; Dijk, van B.; Postma, T.; Klein, M.; Reijneveld, J.

    2008-01-01

    Purpose: In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activ

  9. The influence of low-grade glioma on resting state oscillatory brain activity : a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I; Stam, C J; Douw, L; Bartolomei, F; Heimans, J J; van Dijk, B W; Postma, T J; Klein, M; Reijneveld, J C

    2008-01-01

    PURPOSE: In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activ

  10. Alteration and reorganization of functional networks: a new perspective in brain injury study

    Directory of Open Access Journals (Sweden)

    Nazareth P. Castellanos

    2011-09-01

    Full Text Available Plasticity is the mechanism underlying brain’s potential capability to compensate injury. Recently several studies have shown that functional connections among brain areas are severely altered by brain injury and plasticity leading to a reorganization of the networks. This new approach studies the impact of brain injury by means of alteration of functional interactions. The concept of functional connectivity refers to the statistical interdependencies between physiological time series simultaneously recorded in various brain areas and it could be an essential tool for brain function studies, being its deviation from healthy reference an indicator for damage. In this article, we review studies investigating functional connectivity changes after brain injury and subsequent recovery, providing an accessible introduction to common mathematical methods to infer functional connectivity, exploring their capabilities, future perspectives and clinical uses in brain injury studies.

  11. Brain SCALE: brain structure and cognition: an adolescent longitudinal twin study into the genetic etiology of individual differences.

    Science.gov (United States)

    van Soelen, Inge L C; Brouwer, Rachel M; Peper, Jiska S; van Leeuwen, Marieke; Koenis, Marinka M G; van Beijsterveldt, Toos C E M; Swagerman, Suzanne C; Kahn, René S; Hulshoff Pol, Hilleke E; Boomsma, Dorret I

    2012-06-01

    From childhood into adolescence, the child's brain undergoes considerable changes in both structure and function. Twin studies are of great value to explore to what extent genetic and environmental factors explain individual differences in brain development and cognition. In The Netherlands, we initiated a longitudinal study in which twins, their siblings and their parents are assessed at three year intervals. The participants were recruited from The Netherlands Twin Register (NTR) and at baseline consisted of 112 families, with 9-year-old twins and an older sibling. Three years later, 89 families returned for follow-up assessment. Data collection included psychometric IQ tests, a comprehensive neuropsychological testing protocol, and parental and self-ratings of behavioral and emotional problems. Physical maturation was measured through assessment of Tanner stages. Hormonal levels (cortisol, luteinizing hormone, follicle-stimulating hormone, testosterone, and estrogens) were assessed in urine and saliva. Brain scans were acquired using 1.5 Tesla Magnetic Resonance Imaging (MRI), which provided volumetric measures and measures of cortical thickness. Buccal swabs were collected for DNA isolation for future candidate gene and genome-wide analysis studies. This article gives an overview of the study and the main findings. Participants will return for a third assessment when the twins are around 16 years old. Longitudinal twin-sibling studies that map brain development and cognitive function at well-defined ages aid in the understanding of genetic influences on normative brain development.

  12. Microdialysis study of cefotaxime cerebral distribution in patients with acute brain injury.

    Science.gov (United States)

    Dahyot-Fizelier, Claire; Frasca, Denis; Grégoire, Nicolas; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William; Marchand, Sandrine

    2013-06-01

    Central nervous system (CNS) antibiotic distribution was described mainly from cerebrospinal fluid data, and only few data exist on brain extracellular fluid concentrations. The aim of this study was to describe brain distribution of cefotaxime (2 g/8 h) by microdialysis in patients with acute brain injury who were treated for a lung infection. Microdialysis probes were inserted into healthy brain tissue of five critical care patients. Plasma and unbound brain concentrations were determined at steady state by high-performance liquid chromatography. In vivo recoveries were determined individually using retrodialysis by drug. Noncompartmental and compartmental pharmacokinetic analyses were performed. Unbound cefotaxime brain concentrations were much lower than corresponding plasma concentrations, with a mean cefotaxime unbound brain-to-plasma area under the curve ratio equal to 26.1 ± 12.1%. This result was in accordance with the brain input-to-brain output clearances ratio (CL(in,brain)/CL(out,brain)). Unbound brain concentrations were then simulated at two dosing regimens (4 g every 6 h or 8 h), and the time over the MICs (T>MIC) was estimated for breakpoints of susceptible and resistant Streptococcus pneumoniae strains. T>MIC was higher than 90% of the dosing interval for both dosing regimens for susceptible strains and only for 4 g every 6 h for resistant ones. In conclusion, brain distribution of cefotaxime was well described by microdialysis in patients and was limited.

  13. Studying variability in human brain aging in a population-based German cohort – Rationale and design of 1000BRAINS

    Directory of Open Access Journals (Sweden)

    Svenja eCaspers

    2014-07-01

    Full Text Available The ongoing 1000 brains study (1000BRAINS is an epidemiological and neuroscientific investigation of structural and functional variability in the human brain during aging. The two recruitment sources are the 10-year follow-up cohort of the German Heinz Nixdorf Recall (HNR Study, and the HNR MultiGeneration Study cohort, which comprises spouses and offspring of HNR subjects. The HNR is a longitudinal epidemiological investigation of cardiovascular risk factors, with a comprehensive collection of clinical, laboratory, socioeconomic, and environmental data from population-based subjects aged 45-75 years on inclusion. HNR subjects underwent detailed assessments in 2000, 2006, and 2011, and completed annual postal questionnaires on health status. 1000BRAINS accesses these HNR data and applies a separate protocol comprising: neuropsychological tests of attention, memory, executive functions & language; examination of motor skills; ratings of personality, life quality, mood & daily activities; analysis of laboratory and genetic data; and state-of-the-art magnetic resonance imaging (MRI, 3 Tesla of the brain. The latter includes (i 3D-T1- and 3D-T2-weighted scans for structural analyses and myelin mapping; (ii three diffusion imaging sequences optimized for diffusion tensor imaging, high-angular resolution diffusion imaging for detailed fibre tracking and for diffusion kurtosis imaging; (iii resting-state and task-based functional MRI; and (iv fluid-attenuated inversion recovery and MR angiography for the detection of vascular lesions and the mapping of white matter lesions. The unique design of 1000BRAINS allows: (i comprehensive investigation of various influences including genetics, environment and health status on variability in brain structure and function during aging; and (ii identification of the impact of selected influencing factors on specific cognitive subsystems and their anatomical correlates.

  14. Computational anatomy for studying use-dependant brain plasticity

    Directory of Open Access Journals (Sweden)

    Bogdan eDraganski

    2014-06-01

    Full Text Available In this article we provide a comprehensive literature review on the in vivo assessment of use-dependant brain structure changes in humans using magnetic resonance imaging and computational anatomy. We highlight the recent findings in this field that allow the uncovering of the basic principles behind brain plasticity in light of the existing theoretical models at various scales of observation. Given the current lack of in-depth understanding of the neurobiological basis of brain structure changes we emphasize the necessity of a paradigm shift in the investigation and interpretation of use-dependent brain plasticity. Novel quantitative MRI acquisition techniques provide access to brain tissue microstructural properties (e.g. myelin, iron and water content in-vivo, thereby allowing unprecedented specific insights into the mechanisms underlying brain plasticity. These quantitative MRI techniques require novel methods for image processing and analysis of longitudinal data allowing for straightforward interpretation and causality inferences.

  15. A placebo-controlled, randomized phase II study of maintenance enzastaurin following whole brain radiation therapy in the treatment of brain metastases from lung cancer

    DEFF Research Database (Denmark)

    Grønberg, Bjørn H; Ciuleanu, Tudor; Fløtten, Øystein;

    2012-01-01

    Enzastaurin is a protein kinase C inhibitor with anti-tumor activity. This study was designed to determine if maintenance enzastaurin improved the outcome of whole brain radiotherapy (WBRT) in lung cancer (LC) patients with brain metastases (BMs).......Enzastaurin is a protein kinase C inhibitor with anti-tumor activity. This study was designed to determine if maintenance enzastaurin improved the outcome of whole brain radiotherapy (WBRT) in lung cancer (LC) patients with brain metastases (BMs)....

  16. Vergence in mild traumatic brain injury: A pilot study

    Directory of Open Access Journals (Sweden)

    Dora Szymanowicz, OD, MS

    2012-10-01

    Full Text Available Vergence dysfunction in individuals with mild traumatic brain injury (mTBI may have a negative effect on quality of life, functional abilities, and rehabilitative progress. In this study, we used a range of dynamic and static objective and subjective measures of vergence to assess 21 adult patients with mTBI and nearwork symptoms. The results were compared with 10 control adult subjects. With respect to dynamic parameters, responses in those with mTBI were slowed, variable, and delayed. With respect to static parameters, reduced near point of convergence and restricted near vergence ranges were found in those with mTBI. The present results provide evidence for the substantial adverse effect of mTBI on vergence function.

  17. Intraoperative ultrasonography for presumed brain metastases: a case series study

    Directory of Open Access Journals (Sweden)

    Helder Picarelli

    2012-10-01

    Full Text Available Brain metastases (BM are one of the most common intracranial tumors and surgical treatment can improve both the functional outcomes and patient survival, particularly when systemic disease is controlled. Image-guided BM resection using intraoperative exams, such as intraoperative ultrasound (IOUS, can lead to better surgical results. METHODS: To evaluate the use of IOUS for BM resection, 20 consecutives patients were operated using IOUS to locate tumors, identify their anatomical relationships and surgical cavity after resection. Technical difficulties, complications, recurrence and survival rates were noted. RESULTS: IOUS proved effective for locating, determining borders and defining the anatomical relationships of BM, as well as to identify incomplete tumor resection. No complications related to IOUS were seen. CONCLUSION: IOUS is a practical supporting method for the resection of BM, but further studies comparing this method with other intraoperative exams are needed to evaluate its actual contribution and reliability.

  18. In vivo methods to study uptake of nanoparticles into the brain.

    Science.gov (United States)

    van Rooy, Inge; Cakir-Tascioglu, Serpil; Hennink, Wim E; Storm, Gert; Schiffelers, Raymond M; Mastrobattista, Enrico

    2011-03-01

    Several in vivo techniques have been developed to study and measure the uptake of CNS compounds into the brain. With these techniques, various parameters can be determined after drug administration, including the blood-to-brain influx constant (K(in)), the permeability-surface area (PS) product, and the brain uptake index (BUI). These techniques have been mostly used for drugs that are expected to enter the brain via transmembrane diffusion or by carrier-mediated transcytosis. Drugs that have limitations in entering the brain via such pathways have been encapsulated in nanoparticles (based on lipids or synthetic polymers) to enhance brain uptake. Nanoparticles are different from CNS compounds in size, composition and uptake mechanisms. This has led to different methods and approaches to study brain uptake in vivo. Here we discuss the techniques generally used to measure nanoparticle uptake in addition to the techniques used for CNS compounds. Techniques include visualization methods, behavioral tests, and quantitative methods.

  19. Brain Connectivity Studies in Schizophrenia: Unravelling the Effects of Antipsychotics

    DEFF Research Database (Denmark)

    Nejad, A.B.; Ebdrup, Bjørn Hylsebeck; Glenthøj, Birte Yding;

    2012-01-01

    Impaired brain connectivity is a hallmark of schizophrenia brain dysfunction. However, the effect of drug treatment and challenges on the dysconnectivity of functional networks in schizophrenia is an understudied area. In this review, we provide an overview of functional magnetic resonance imaging...

  20. Continuous infusion of proinflammatory cytokines into the brain to study brain cytokine induced local and systemic immune effects.

    Science.gov (United States)

    Schöning, B; Elepfandt, P; Lanksch, W R; Volk, H D; Woiciechowsky, C

    1999-07-01

    Proinflammatory cytokines are produced in the brain after various kinds of insult (ischemia, trauma, infection). In this process interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha are most important. These cytokines are key mediators of inflammation. Furthermore, these cytokines can act as neurotransmitters and develop direct effects on the central nervous system (CNS) including fever, sleep and stimulation of the neuroendocrine as well as sympathetic nervous system. Moreover, IL-1beta and TNF-alpha may also be involved in brain repair and regenerating processes. However, most of the data about the role of cytokines in the brain have been obtained from either in vitro studies or bolus injections into the brain parenchyma or cerebroventricular system. On the other hand, it is known that cytokines are released continuously into the brain after a cerebral insult over a period of 24 to 48 h. In order to further complete the knowledge about the interactions between neural and immune cells to overcome the primary insult and initiate repair and regeneration in the CNS, a new animal model of local inflammation reaction was established using chronic intracerebral infusion of rat recombinant cytokines.

  1. The automatic brain: studies on practice and brain function in healthy subjects and patients with schizophrenia

    NARCIS (Netherlands)

    van Raalten, T.R.

    2009-01-01

    Practice makes perfect. The neural mechanisms behind the behavioral improvement of practice (automatization) however are largely unknown. Here we investigate how practice changes brain function and how this can improve our processing capacity. We also examine whether a deficit in automatization can

  2. BRAIN VOLUMES OF THE LAMB, RAT AND BIRD DO NOT SHOW HEMISPHERIC ASYMMETRY: A STEREOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Bünyamin Sahin

    2011-05-01

    Full Text Available It is well known that there are functional differences between right and left brain hemispheres. However, it is not clear whether these functional differences are reflected in morphometric differences. This study was carried out to investigate the right-left asymmetry, and sex and species differences of the brains using the Cavalieri principle for volume estimation. Seventeen lambs, 10 rats and 12 avian brains were used to estimate brain volumes. A transparent point grid was superimposed on the slices of lamb brains directly and the slices of the rat and avian brains were projected onto a screen at 10x magnification. Surface areas of the cut slice faces were estimated by simply counting the points that hit the slices. Mean brain volumes were 37.74 cm3, 598.95 mm3 and 730.38 mm3 and the coefficients of variations were 0.08, 0.05 and 0.05 for lamb, rat and avian brains respectively. The differences between left and right hemispheres did not show statistical significance (P > 0.05. However, the male brain volumes were larger than the females for the lamb and bird (P < 0.05. In light of such findings, it will be necessary to evaluate neuron number of the brain hemispheres to provide more useful data regarding inter-hemispheric brain asymmetry.

  3. Study of Posterior Cerebral Artery in Human Cadaveric Brain

    Directory of Open Access Journals (Sweden)

    S. A. Gunnal

    2015-01-01

    Full Text Available Objective. Basilar artery (BA terminates in right and left posterior cerebral arteries (PCAs. Each PCA supplies respective occipital lobe of the cerebrum. The present study is designed to know the morphology, morphometry, branching pattern, and symmetry of PCA. Methods. The study included 340 PCAs dissected from 170 human cadaveric brains. Results. Morphological variations of P1 segment included, aplasia (2.35%, hypoplasia (5.29%, duplication (2.35%, fenestration (1.17%, and common trunk shared with SCA (1.76%. Morphological variations of origin of P2 segment included direct origin of it from BA (1.17% and ICA (2.35%. Unusually, two P2 segments, each arising separately from BA and ICA, were observed in 1.17%. Unilateral two P2 segments from CW were found in 0.58%. Morphological variations of course of P2 were duplication (0.58%, fenestration (0.58%, and aneurysm (1.76%. Unilateral P2 either adult or fetal was seen in 4.71%. The group II branching pattern was found to be most common. Asymmetry of P2 was 40%. Morphometry of P2 revealed mean length of 52 mm and mean diameter of 2.7 mm. Conclusion. The present study provides the complete anatomical description of PCA regarding morphology, morphometry, symmetry, and its branching pattern. Awareness of these variations is likely to be useful in cerebrovascular procedures.

  4. Myocardial function at the early phase of traumatic brain injury: a prospective controlled study

    OpenAIRE

    Cuisinier, Adrien; Maufrais, Claire; Payen, Jean-François; Nottin, Stephane; Walther, Guillaume; Bouzat, Pierre

    2016-01-01

    Background The concept of brain-heart interaction has been described in several brain injuries. Traumatic brain injury (TBI) may also lead to cardiac dysfunction but evidences are mainly based upon experimental and clinical retrospective studies. Methods We conducted a prospective case-control study in a level I trauma center. Twenty consecutive adult patients with severe TBI were matched according to age and gender with 20 control patients. The control group included adult patients undergoin...

  5. Brain-computer interfacing under distraction: an evaluation study

    Science.gov (United States)

    Brandl, Stephanie; Frølich, Laura; Höhne, Johannes; Müller, Klaus-Robert; Samek, Wojciech

    2016-10-01

    Objective. While motor-imagery based brain-computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach. This paper systematically investigates BCI performance under 6 types of distractions that mimic out-of-lab environments. Main results. We report results of 16 participants and show that the performance of the standard common spatial patterns (CSP) + regularized linear discriminant analysis classification pipeline drops significantly in this ‘simulated’ out-of-lab setting. We then investigate three methods for improving the performance: (1) artifact removal, (2) ensemble classification, and (3) a 2-step classification approach. While artifact removal does not enhance the BCI performance significantly, both ensemble classification and the 2-step classification combined with CSP significantly improve the performance compared to the standard procedure. Significance. Systematically analyzing out-of-lab scenarios is crucial when bringing BCI into everyday life. Algorithms must be adapted to overcome nonstationary environments in order to tackle real-world challenges.

  6. Sincipital Encephaloceles: A Study of Associated Brain Malformations

    Directory of Open Access Journals (Sweden)

    Shashidhar Vedavyas Achar

    2016-01-01

    Full Text Available Objective: The aim of this study was to evaluate the associated intracranial malformations in patients with sincipital encephaloceles. Materials and Methods: A hospital-based cross-sectional study was conducted over 8 years from June 2007 to May 2015 on 28 patients. The patients were evaluated by either computed tomography or magnetic resonance imaging whichever was feasible. Encephaloceles were described with respect to their types, contents, and extensions. A note was made on the associated malformations with sincipital encephaloceles. Results: Fifty percent of the patients presented before the age of 3 years and both the sexes were affected equally. Nasofrontal encephalocele was the most common type seen in 13 patients (46.4%, and corpus callosal agenesis (12 patients was the most common associated malformation. Other malformations noted were arachnoid cyst (10 patients, hydrocephalus (7 patients, and agyria-pachygyria complex (2 patients. Conclusion: Capital Brain malformations are frequently encountered in children with sincipital encephaloceles. Detail radiological evaluation is necessary to plan treatment and also to prognosticate such rare malformations.

  7. Extracellular Hsp90 as a Novel Epigenetic of EMT and Metastatic Risk in Prostate Cancer

    Science.gov (United States)

    2015-12-01

    Res. 68, 2479 –2488 16. Xie, D., Gore, C., Liu, J., Pong, R. C., Mason , R., Hao, G., Long, M., Kabbani, W., Yu, L., Zhang, H., Chen, H., Sun, X...cell migration and invasion. J. Biol. Chem. 288, 9001–9010 20. Burgess, E. F., Ham, A. J., Tabb, D. L., Billheimer, D., Roth , B. J., Chang, S. S

  8. Clinical Development of Gamitrinib, a Novel Mitochondrial-Targeted Small Molecule Hsp90 Inhibitor

    Science.gov (United States)

    2015-09-01

    trophoblast, an actively invasive tissue at the interface between fetal and maternal circulation [30], whereas expression of this molecule in the adult...chondrial survivin (3). Furthermore, reconstitution of survivin-depleted PC3 cells with adenovirus ( pAd ) encoding mitochondrial-targeted survivin (3... pAd - mt-SVV) stimulated O2 consumption (Fig. 2G). In contrast, PC3 cells transfected with nontargeting siRNA and reconstituted with pAd -mt-survivin

  9. Hsp40s specify functions of Hsp104 and Hsp90 protein chaperone machines.

    Directory of Open Access Journals (Sweden)

    Michael Reidy

    2014-10-01

    Full Text Available Hsp100 family chaperones of microorganisms and plants cooperate with the Hsp70/Hsp40/NEF system to resolubilize and reactivate stress-denatured proteins. In yeast this machinery also promotes propagation of prions by fragmenting prion polymers. We previously showed the bacterial Hsp100 machinery cooperates with the yeast Hsp40 Ydj1 to support yeast thermotolerance and with the yeast Hsp40 Sis1 to propagate [PSI+] prions. Here we find these Hsp40s similarly directed specific activities of the yeast Hsp104-based machinery. By assessing the ability of Ydj1-Sis1 hybrid proteins to complement Ydj1 and Sis1 functions we show their C-terminal substrate-binding domains determined distinctions in these and other cellular functions of Ydj1 and Sis1. We find propagation of [URE3] prions was acutely sensitive to alterations in Sis1 activity, while that of [PIN+] prions was less sensitive than [URE3], but more sensitive than [PSI+]. These findings support the ideas that overexpressing Ydj1 cures [URE3] by competing with Sis1 for interaction with the Hsp104-based disaggregation machine, and that different prions rely differently on activity of this machinery, which can explain the various ways they respond to alterations in chaperone function.

  10. Clinical Development of Gamitrinib, a Novel Mitochondrial-Targeted Small Molecule Hsp90 Inhibitor

    Science.gov (United States)

    2014-09-01

    with mitochondrial proteins, including cyclophilin D (CypD), a component of the permeability transition pore and control their folding19. Accordingly...pheochromocytoma. N. Engl. J. Med. 346, 1459–1466 (2002). 36. King , A., Selak, M. A. & Gottlieb, E. Succinate dehydrogenase and fumarate hydratase: linking

  11. Imaging Heat Shock Protein 90 (Hsp90) Activity in Hormone-Refractory Prostate Cancer

    Science.gov (United States)

    2011-01-01

    then purified by PD-10 column using phosphate-buffered saline (PBS) as the mobile phase. The labeling yield was calculated by dividing the decay...shaking. 64Cu- DOTA–cetuximab was then purified by PD-10 column using PBS as the mobile phase. PET of tumor-bearing mice was performed on a microPET R4...measurement of protein–protein interactions in vivo. sing the “fluorescence recovery after photobleaching” (FRAP) echnology , for instance, Picard [74

  12. Extracellular Hsp90 as a Novel Epigenetic of EMT and Metastatic Risk in Prostate Cancer

    Science.gov (United States)

    2014-10-01

    d E R K 2 su pp re ss io n ha d lit tle e ffe ct (m id dl e an d bo tto m p an el s) . C ) G ra ph ic al r ep re se nt at io n of th...d bo tto m p an el s) . E) G ra ph ic al r ep re se nt at io n of th e fo ld c ha ng es in A LD H 1A 1 ac tiv ity b et w ee n A R C aP

  13. Modulating EGFR Signaling by Targeting the Deacetylase HDAC6-Hsp90 Complex in Breast Tumors

    Science.gov (United States)

    2007-06-01

    the supernatant, referred to as “cytosol,” was collected, aliquotted, flash-frozen, and stored at 70 °C. Mouse GR was expressed in Sf9 cells, and...steroid binding) or 100 l (forWestern blotting) of Sf9 cell cytosol by rotation for 2 h at 4 °C with 18 l of protein A-Sepharose precoupled to 10 l...of Sf9 cell cytosol. Gel Electrophoresis and Western Blotting—Immune pellets were resolved on 12% SDS-polyacrylamide gels and transferred to

  14. Revisiting hydrocephalus as a model to study brain resilience.

    Directory of Open Access Journals (Sweden)

    Matheus Fernandes De Oliveira

    2012-01-01

    Full Text Available Hydrocephalus is an entity which embraces a variety of diseases whose final result is the enlarged size of cerebral ventricular system, partially or completely. The physiopathology of hydrocephalus lies in the dynamics of circulation of cerebrospinal fluid (CSF. The consequent CSF stasis in hydrocephalus interferes with cerebral and ventricular system development. Children and adults who sustain congenital or acquired brain injury typically experience a diffuse insult that impacts many areas of the brain. Development and recovery after such injuries reflects both restoration and reorganization of cognitive functions. Classic examples were already reported in literature. This suggests the presence of biological mechanisms associated with resilient adaptation of brain networks. We will settle a link between the notable modifications to neurophysiology secondary to hydrocephalus and the ability of neuronal tissue to reassume and reorganize its functions.Key words: hydrocephalus; resilience; brain; neural networks; plasticity.

  15. Neurogenic fever after traumatic brain injury: an epidemiological study

    OpenAIRE

    Thompson, H; Pinto-Martin, J; Bullock, M.

    2003-01-01

    Objectives: To determine the incidence of neurogenic fever (NF) in a population of patients in the acute phase following severe traumatic brain injury (TBI); to identify factors associated with the development of NF following severe TBI in adults.

  16. Weight Gain following Pallidal Deep Brain Stimulation: A PET Study

    OpenAIRE

    Sauleau, Paul; Drapier, Sophie; Duprez, Joan; Houvenaghel, Jean-François; Dondaine, Thibaut; Haegelen, Claire; Drapier, Dominique; Jannin, Pierre; Robert, Gabriel; Le Jeune, Florence; Vérin, Marc

    2016-01-01

    The mechanisms behind weight gain following deep brain stimulation (DBS) surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN) or the globus pallidus internus (GPi). Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET) and weight gain following GPi...

  17. Neurophotonics: optical methods to study and control the brain

    Science.gov (United States)

    Doronina-Amitonova, L. V.; Fedotov, I. V.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

    2015-04-01

    Methods of optical physics offer unique opportunities for the investigation of brain and higher nervous activity. The integration of cutting-edge laser technologies and advanced neurobiology opens a new cross-disciplinary area of natural sciences - neurophotonics - focusing on the development of a vast arsenal of tools for functional brain diagnostics, stimulation of individual neurons and neural networks, and the molecular engineering of brain cells aimed at the diagnosis and therapy of neurodegenerative and psychic diseases. Optical fibers help to confront the most challenging problems in brain research, including the analysis of molecular-cellular mechanisms of the formation of memory and behavior. New generation optical fibers provide new solutions for the development of fundamentally new, unique tools for neurophotonics and laser neuroengineering - fiber-optic neuroendoscopes and neurointerfaces. These instruments broaden research horizons when investigating the most complex brain functions, enabling a long-term multiplex detection of fluorescent protein markers, as well as photostimulation of neuronal activity in deep brain areas in living, freely moving animals with an unprecedented spatial resolution and minimal invasiveness. This emerging technology opens new horizons for understanding learning and long-term memory through experiments with living, freely moving mammals. Here, we present a brief review of this rapidly growing field of research.

  18. Upregulation and intrarenal redistribution of heat shock proteins 90α and 90β by low-sodium diet in the rat

    Science.gov (United States)

    Ramírez, Victoria; Uribe, Norma; García-Torres, Romeo; Castro, Clementina; Rubio, Julieta; Gamba, Gerardo; Bobadilla, Norma A.

    2004-01-01

    Two genes encoding isoforms heat shock protein (Hsp) 90α and Hsp90β constitute the Hsp90 subfamily. In addition to their role in regulating mineralocorticoid and glucocorticoid receptors, these proteins have been associated with nitric oxide production. However, little is known regarding Hsp90 isoform expression and regulation in kidney. In this study we characterized the expression and localization of Hsp90 isoforms and evaluated the influence of low-sodium intake on their expression and distribution in kidney by using reverse transcription–polymerase chain reaction, Western blot, and immunohistochemistry techniques. We found that Hsp90α and Hsp90β were expressed abundantly in both the renal cortex and the medulla; however, Hsp90 isoform expression was higher in the medulla than in the cortex. Immunohistochemistry of Hsp90α and Hsp90β showed intense staining in the apical membrane of proximal and distal tubules. In the outer cortex these proteins were localized intracytosolically, whereas in the inner renal medulla they were restricted mainly to the basolateral membrane. Expression of Hsp90α and Hsp90β was upregulated in the renal cortex during sodium restriction. In addition, both proteins exhibited redistribution from the cytoplasm to the basolateral side in thick ascending limb cells when rats were fed with a low-salt diet. Our results showed that Hsp90α and Hsp90β were expressed abundantly in renal tissue. Expression and localization patterns under normal and salt-restricted intake were different between the cortex and the medulla, suggesting that these proteins may be involved in different processes along the nephron. Hsp90α and Hsp90β upregulation induced by a low-sodium diet together with redistribution in thick ascending limb cells suggests that Hsp90 plays a role in the modulation of sodium reabsorption under these circumstances. PMID:15497505

  19. The calculating hemispheres: studies of a split-brain patient.

    Science.gov (United States)

    Funnell, Margaret G; Colvin, Mary K; Gazzaniga, Michael S

    2007-06-11

    The purpose of the study was to investigate simple calculation in the two cerebral hemispheres of a split-brain patient. In a series of four experiments, the left hemisphere was superior to the right in simple calculation, confirming the previously reported left hemisphere specialization for calculation. In two different recognition paradigms, right hemisphere performance was at chance for all arithmetic operations, with the exception of subtraction in a two-alternative forced choice paradigm (performance was at chance when the lure differed from the correct answer by a magnitude of 1 but above chance when the magnitude difference was 4). In a recall paradigm, the right hemisphere performed above chance for both addition and subtraction, but performed at chance levels for multiplication and division. The error patterns in that experiment suggested that for subtraction and addition, the right hemisphere does have some capacity for approximating the solution even when it is unable to generate the exact solution. Furthermore, right hemisphere accuracy in addition and subtraction was higher for problems with small operands than with large operands. An additional experiment assessed approximate and exact addition in the two hemispheres for problems with small and large operands. The left hemisphere was equally accurate in both tasks but the right hemisphere was more accurate in approximate addition than in exact addition. In exact addition, right hemisphere accuracy was higher for problems with small operands than large, but the opposite pattern was found for approximate addition.

  20. Folic acid in the monkey brain: an immunocytochemical study.

    Science.gov (United States)

    Mangas, A; Coveñas, R; Geffard, K; Geffard, M; Marcos, P; Insausti, R; Dabadie, M P

    2004-05-27

    The present report describes the first visualization of folic acid-immunoreactive fibers in the mammalian central nervous system using a highly specific antiserum directed against this vitamin. The distribution of folic acid-immunoreactive structures was studied in the brainstem and thalamus of the monkey using an indirect immunoperoxidase technique. We observed fibers containing folic acid, but no folic acid-immunoreactive cell bodies were found. In the brainstem, no immunoreactive structures were visualized in the medulla oblongata, pons, or in the medial-caudal mesencephalon, since at this location immunoreactive fibers containing folic acid were only found at the rostral level in the dorsolateral mesencephalon (in the mesencephalic-diencephalic junction). In the thalamus, the distribution of folic acid-immunoreactive structures was more widespread. Thus, we found immunoreactive fibers in the midline, in nuclei close to the midline (dorsomedial nucleus, centrum medianum/parafascicular complex), in the ventral region of the thalamus (ventral posteroinferior nucleus, ventral posteromedial nucleus), in the ventrolateral thalamus (medial geniculate nucleus, lateral geniculate nucleus, inferior pulvinar nucleus) and in the dorsolateral thalamus (lateral posterior nucleus, pulvinar nucleus). The highest density of fibers containing folic acid was observed in the dorsolateral mesencephalon and in the pulvinar nucleus. The distribution of folic acid-immunoreactive structures in the monkey brain suggests that this vitamin could be involved in several mechanisms, such as visual, auditory, motor and somatosensorial functions.

  1. Brain-Based Learning and Classroom Practice: A Study Investigating Instructional Methodologies of Urban School Teachers

    Science.gov (United States)

    Morris, Lajuana Trezette

    2010-01-01

    The purpose of this study was to examine the implementation of brain-based instructional strategies by teachers serving at Title I elementary, middle, and high schools within the Memphis City School District. This study was designed to determine: (a) the extent to which Title I teachers applied brain-based strategies, (b) the differences in…

  2. Diffusion Tensor Imaging: Application to the Study of the Developing Brain

    Science.gov (United States)

    Cascio, Carissa J.; Gerig, Guido; Piven, Joseph

    2007-01-01

    Objective: To provide an overview of diffusion tensor imaging (DTI) and its application to the study of white matter in the developing brain in both healthy and clinical samples. Method: The development of DTI and its application to brain imaging of white matter tracts is discussed. Forty-eight studies using DTI to examine diffusion properties of…

  3. A phase 2 study of radiosurgery and temozolomide for patients with 1 to 4 brain metastases

    Directory of Open Access Journals (Sweden)

    John B. Fiveash, MD

    2016-04-01

    Conclusions: In this study, there was a relatively low risk of distant brain failure observed in the nonmelanoma subgroup receiving temozolamide. However, patient selection factors rather than chemotherapy treatment efficacy are more likely the reason for the relatively low risk of distant brain failure observed in this study. Future trial design should account for these risk factors.

  4. [Study of cytokines content and gangliosides metabolism at experimental brain edema].

    Science.gov (United States)

    Zakarian, A V; Kazarian, G S; Zakarian, G V; Melkonian, M M; Ovsesian, L M

    2011-01-01

    The content of cytokines, and gangliosides metabolism, and the quantity of lipid peroxidation products were studied at experimental brain edema. Data obtained show increase the level of proinflammatory cytokins and decrease the level of antiinflammatory cytokines during development of brain edema. Along with this we reveal the accumulation of lipid peroxidation products (diene conjugates, hydroperoxides, and malonic dialdehyde). Each fraction of gangliosides decreased, but the product of their hydrolytic dissociation sphingosine increased at experimental brain edema.

  5. Reduction in heat shock protein 90 correlates to neuronal vulnerability in the rat piriform cortex following status epilepticus.

    Science.gov (United States)

    Kim, Y-J; Kim, J-Y; Ko, A-R; Kang, T-C

    2013-01-01

    In the present study, we addressed the question of whether the distinct patterns of heat shock protein (HSP) 70 and HSP90 expressions in the brain region represents the regional specific responses to status epilepsticus (SE) in an effort to better understand the role of HSPs in epileptogenic insult. HSP70 immunoreactivity was increased in CA3 pyramidal cells as well as dentate granule cells at 12h-1week after SE. HSP70 immunoreactivity was transiently increased in neurons within the piriform cortex (PC) following SE. Linear regression analysis showed no correlation between the intensity of NeuN and that of HSP70. In contrast to HSP70, HSP90 immunoreactivity was decreased in CA1-3 pyramidal cells at 4days-4weeks after SE. In addition, HSP90 immunoreactivity was decreased in PC neurons at 12h-4weeks after SE. linear regression analysis showed a direct proportional relationship between the intensity of NeuN and that of HSP90. Therefore, these findings suggest that HSP90 degradation may be closely related to neuronal vulnerability to SE insult.

  6. CT ASSESSMENT OF BRAIN VENTRICULAR SIZE BASED ON AGE AND SEX: A STUDY OF 112 CASES

    Directory of Open Access Journals (Sweden)

    Vinoo

    2013-12-01

    Full Text Available CT being the primary modality of choice in many centers for the diagnosis of brain pathology, normal brain ventricular size measurem ents is an important parameter for the diagnosis of conditions like hydrocephalus, age related atrophic changes and also other brain pathologies producing ventriculomegaly. It is also important for knowing the normal upper and lower limits of the brain ven tricular system in the different age groups, and in both sexes so as to diagnose brain pathology.The ventricular system of the brain undergoes changes with aging and varies with gender.Our study consists of 48 female, and 64 male patients. Apart from the v entricular measurements, two ratios and two indices were also calculated – which included the right and left Evan’s ratio, CM index, and ventricular size inde

  7. The brain, obesity and addiction: an EEG neuroimaging study

    Science.gov (United States)

    De Ridder, Dirk; Manning, Patrick; Leong, Sook Ling; Ross, Samantha; Sutherland, Wayne; Horwath, Caroline; Vanneste, Sven

    2016-01-01

    Obesity is among the greatest challenges facing healthcare systems with 20% of the world’s population afflicted. Great controversy exists whether obesity can be regarded as an addictive disorder or not. Recently the Yale Food Addiction Scale questionnaire has been developed as a tool to identify individuals with traits of addiction towards food. Using clinical and source localized EEG data we dichotomize obesity. Brain activity in food-addicted and non-food-addicted obese people is compared to alcohol-addicted and non-addicted lean controls. We show that food addiction shares common neural brain activity with alcohol addiction. This ‘addiction neural brain activity’ consists of the dorsal and pregenual anterior cingulate cortex, parahippocampal area and precuneus. Furthermore, common neural obesity neural brain activity exists as well. The ‘obesity neural brain activity’ consists of dorsal and pregenual anterior cingulate cortex, posterior cingulate extending into the precuneus/cuneus as well as the parahippocampal and inferior parietal area. However food-addicted differ from non-food-addicted obese people by opposite activity in the anterior cingulate gyrus. This food addiction and non-food-addiction obesity dichotomy demonstrates there is at least 2 different kinds of obesity with overlapping network activity, but different in anterior cingulate cortex activity. PMID:27658351

  8. Sex steroids and connectivity in the human brain: a review of neuroimaging studies.

    Science.gov (United States)

    Peper, Jiska S; van den Heuvel, Martijn P; Mandl, René C W; Hulshoff Pol, Hilleke E; van Honk, Jack

    2011-09-01

    Our brain operates by the way of interconnected networks. Connections between brain regions have been extensively studied at a functional and structural level, and impaired connectivity has been postulated as an important pathophysiological mechanism underlying several neuropsychiatric disorders. Yet the neurobiological mechanisms contributing to the development of functional and structural brain connections remain to be poorly understood. Interestingly, animal research has convincingly shown that sex steroid hormones (estrogens, progesterone and testosterone) are critically involved in myelination, forming the basis of white matter connectivity in the central nervous system. To get insights, we reviewed studies into the relation between sex steroid hormones, white matter and functional connectivity in the human brain, measured with neuroimaging. Results suggest that sex hormones organize structural connections, and activate the brain areas they connect. These processes could underlie a better integration of structural and functional communication between brain regions with age. Specifically, ovarian hormones (estradiol and progesterone) may enhance both cortico-cortical and subcortico-cortical functional connectivity, whereas androgens (testosterone) may decrease subcortico-cortical functional connectivity but increase functional connectivity between subcortical brain areas. Therefore, when examining healthy brain development and aging or when investigating possible biological mechanisms of 'brain connectivity' diseases, the contribution of sex steroids should not be ignored.

  9. A study of brain MRI findings and clinical response of bladder empting failure in brain bladder

    Energy Technology Data Exchange (ETDEWEB)

    Miyakoda, Keiichi (Yamashina Aiseikai Hospital, Kyoto (Japan)); Watanabe, Kousuke

    1993-02-01

    In 45 patients (38 males and 7 females; average age:78 years) with brain bladder, who did not have any peripheral neuropathies and spinal disturbance, cerebral findings of MRI (1.5 T) T[sub 2] enhanced image were analyzed in comparison with those of 7 control patients with normal urination after BPH operations. Patients with neurogenic bladder were divided into three groups as follows: 33 patients with a chief complaint of urinary disturbance (Group I), 9 patients with urinary incontinence (Group II) and 3 patients with balanced bladder (Group III). High frequency of lacune (24%) of the globus pallidus and low signalling of the corpus striatum (30%) was found in Group I patients, but low frequency in other Group patients and control patients. Furthermore, pathologic changes with various grades in the globus pallidus were observed in 91% of Group I patients. In the treatment of urinary disturbance, a high improvement rate of micturition disorder (77%) was obtained in patients treated with a combination of dantrolene and TURp (TUIbn for females). However, patients who had clear lacune of the globus pallidus showed the low improvement rate. It should be possible that the globus pallidus contributes to control the movement of the external sphincter and the pelvic base muscles as well as other striated muscles. Moreover, lacune was rarely found in the urination center of the brain-stem on MRI. (author).

  10. Traumatic Brain Injury Studies in Britain during World War II.

    Science.gov (United States)

    Lanska, Douglas J

    2016-01-01

    As a result of the wartime urgency to understand, prevent, and treat patients with traumatic brain injury (TBI) during World War II (WWII), clinicians and basic scientists in Great Britain collaborated on research projects that included accident investigations, epidemiologic studies, and development of animal and physical models. Very quickly, investigators from different disciplines shared information and ideas that not only led to new insights into the mechanisms of TBI but also provided very practical approaches for preventing or ameliorating at least some forms of TBI. Neurosurgeon Hugh Cairns (1896-1952) conducted a series of influential studies on the prevention and treatment of head injuries that led to recognition of a high rate of fatal TBI among motorcycle riders and subsequently to demonstrations of the utility of helmets in lowering head injury incidence and case fatality. Neurologists Derek Denny-Brown (1901-1981) and (William) Ritchie Russell (1903-1980) developed an animal model of TBI that demonstrated the fundamental importance of sudden acceleration (i.e., jerking) of the head in causing concussion and forced a distinction between head injury associated with sudden acceleration/deceleration and that associated with crush or compression. Physicist A.H.S. Holbourn (1907-1962) used theoretical arguments and simple physical models to illustrate the importance of shear stress in TBI. The work of these British neurological clinicians and scientists during WWII had a strong influence on subsequent clinical and experimental studies of TBI and also eventually resulted in effective (albeit controversial) public health campaigns and legislation in several countries to prevent head injuries among motorcycle riders and others through the use of protective helmets. Collectively, these studies accelerated our understanding of TBI and had subsequent important implications for both military and civilian populations. As a result of the wartime urgency to understand

  11. Calcium uptake in brain synaptosomes: a pharmacologic study

    Energy Technology Data Exchange (ETDEWEB)

    Rampe, D.E.

    1986-01-01

    Pinched-off nerve endings (synaptosomes) from rat and guinea pig brain were used as a model to study Ca/sup 2 +/ entry mechanisms in neuronal tissue. Synaptosomes contain high affinity binding sites for both, 1,4-dihydropyridine Ca/sup 2 +/ channel antagonists, and activators. The thermodynamic characteristics of (/sup 3/H)nitrendipine building in synaptosomes were similar to those seen in both cardiac and smooth muscle preparations. Synaptosomes display two distinct K/sup +/-induced Ca/sup 2 +/ entry mechanisms. These are kinetically distinct with the faster of the two terminating in approx. 1 second while the slower persists for approx. minute. The slow phase uptake process is abolished in Na/sup +/-free media, is sensitive to antagonism by 3,4-dichlorobenzamil and displays a more rapid ontogenic appearance relative to the fast phase. It is likely that the slow phase represents Ca/sup 2 +/ entry via Na/sup +//Ca/sup 2 +/ exchange. The rapid inactivation of the fast phase coupled with its voltage dependence suggest that it represents Ca/sup 2 +/ entry via one or more types of voltage dependent Ca/sup 2 +/ channels. These channels may not be dihydropyridin sensitive since neither nitrendipine nor Bay K 8644 were shown to modulate synaptosomal Ca/sup 2 +/ uptake. The benzodiazepine receptor ligands Ro 5-4864, PK 11195 and diazepam all selectively inhibited fast phase Ca/sup 2 +/ entry relative to slow phase entry. In addition, these compounds altered (/sup 3/H)nitrendipine binding affinity. It is concluded that certain benzodiazepine receptor ligands can interact specifically with voltage dependent Ca/sup 2 +/ channels.

  12. Validation of a method for accurate and highly reproducible quantification of brain dopamine transporter SPECT studies

    DEFF Research Database (Denmark)

    Jensen, Peter S; Ziebell, Morten; Skouboe, Glenna

    2011-01-01

    In nuclear medicine brain imaging, it is important to delineate regions of interest (ROIs) so that the outcome is both accurate and reproducible. The purpose of this study was to validate a new time-saving algorithm (DATquan) for accurate and reproducible quantification of the striatal dopamine...... transporter (DAT) with appropriate radioligands and SPECT and without the need for structural brain scanning....

  13. Development of luciferase tagged brain tumour models in mice for chemotherapy intervention studies.

    NARCIS (Netherlands)

    Kemper, E.M.; Leenders, W.P.J.; Kusters, B.; Lyons, S.; Buckle, T.; Heerschap, A.; Boogerd, W.; Beijnen, J.H.; Tellingen, O.

    2006-01-01

    The blood-brain barrier (BBB) is considered one of the major causes for the low efficacy of cytotoxic compounds against primary brain tumours. The aim of this study was to develop intracranial tumour models in mice featuring intact or locally disrupted BBB properties, which can be used in testing ch

  14. Domiciliary therapy during inpatient rehabilitation treatment for patients with an acquired brain injury : A preliminary study

    NARCIS (Netherlands)

    Boonstra, AM; Spikman, JM; Wijbrandi, Wilma

    2005-01-01

    The objective was to assess the feasibility of additional domiciliary treatment for patients with an acquired brain injury while they are still inpatients at a rehabilitation centre. This cohort study included 22 patients with an acquired brain injury (mainly stroke) and with moderate to severe neur

  15. Effects of motor fatigue on human brain activity, an fMRI study

    NARCIS (Netherlands)

    van Duinen, Hiske; Renken, Remco; Maurits, Natasha; Zijdewind, Inge

    2007-01-01

    The main purpose of this study was to investigate effects of motor fatigue on brain activation in humans, using fMRI. First, we assessed brain activation that correlated with muscle activity during brief contractions at different force levels (force modulation). Second, a similar analysis was done f

  16. A Comparative Study of Theoretical Graph Models for Characterizing Structural Networks of Human Brain

    Directory of Open Access Journals (Sweden)

    Xiaojin Li

    2013-01-01

    Full Text Available Previous studies have investigated both structural and functional brain networks via graph-theoretical methods. However, there is an important issue that has not been adequately discussed before: what is the optimal theoretical graph model for describing the structural networks of human brain? In this paper, we perform a comparative study to address this problem. Firstly, large-scale cortical regions of interest (ROIs are localized by recently developed and validated brain reference system named Dense Individualized Common Connectivity-based Cortical Landmarks (DICCCOL to address the limitations in the identification of the brain network ROIs in previous studies. Then, we construct structural brain networks based on diffusion tensor imaging (DTI data. Afterwards, the global and local graph properties of the constructed structural brain networks are measured using the state-of-the-art graph analysis algorithms and tools and are further compared with seven popular theoretical graph models. In addition, we compare the topological properties between two graph models, namely, stickiness-index-based model (STICKY and scale-free gene duplication model (SF-GD, that have higher similarity with the real structural brain networks in terms of global and local graph properties. Our experimental results suggest that among the seven theoretical graph models compared in this study, STICKY and SF-GD models have better performances in characterizing the structural human brain network.

  17. Brain Potentials for Derivational Morphology: An ERP Study of Deadjectival Nominalizations in Spanish

    Science.gov (United States)

    Havas, Viktoria; Rodriguez-Fornells, Antoni; Clahsen, Harald

    2012-01-01

    This study investigates brain potentials to derived word forms in Spanish. Two experiments were performed on derived nominals that differ in terms of their productivity and semantic properties but are otherwise similar, an acceptability judgment task and a reading experiment using event-related brain potentials (ERPs) in which correctly and…

  18. Heterogeneity in subcortical brain development: A structural magnetic resonance imaging study of brain maturation from 8 to 30 years.

    Science.gov (United States)

    Ostby, Ylva; Tamnes, Christian K; Fjell, Anders M; Westlye, Lars T; Due-Tønnessen, Paulina; Walhovd, Kristine B

    2009-09-23

    Brain development during late childhood and adolescence is characterized by decreases in gray matter (GM) and increases in white matter (WM) and ventricular volume. The dynamic nature of development across different structures is, however, not well understood, and the present magnetic resonance imaging study took advantage of a whole-brain segmentation approach to describe the developmental trajectories of 16 neuroanatomical volumes in the same sample of children, adolescents, and young adults (n = 171; range, 8-30 years). The cerebral cortex, cerebral WM, caudate, putamen, pallidum, accumbens area, hippocampus, amygdala, thalamus, brainstem, cerebellar GM, cerebellar WM, lateral ventricles, inferior lateral ventricles, third ventricle, and fourth ventricle were studied. The cerebral cortex was further analyzed in terms of lobar thickness and surface area. The results revealed substantial heterogeneity in developmental trajectories. GM decreased nonlinearly in the cerebral cortex and linearly in the caudate, putamen, pallidum, accumbens, and cerebellar GM, whereas the amygdala and hippocampus showed slight, nonlinear increases in GM volume. WM increased nonlinearly in both the cerebrum and cerebellum, with an earlier maturation in cerebellar WM. In addition to similarities in developmental trajectories within subcortical regions, our results also point to differences between structures within the same regions: among the basal ganglia, the caudate showed a weaker relationship with age than the putamen and pallidum, and in the cerebellum, differences were found between GM and WM development. These results emphasize the importance of studying a wide range of structural variables in the same sample, for a broader understanding of brain developmental principles.

  19. Brain activity during driving with distraction: an immersive fMRI study

    Directory of Open Access Journals (Sweden)

    Tom A Schweizer

    2013-02-01

    Full Text Available Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns to more complex (left turns at busy intersections. To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research.

  20. Fertility, aging and the brain neuroendocrinological studies in female rats

    NARCIS (Netherlands)

    Franke, A.N.

    2003-01-01

    It is well known that fertility decreases in female mammals with advancing age. In women this decrease already starts around the age of 30 and shows a large variation between individuals. The aim of this thesis was to elucidate changes in the reproductive system, especially in the brain, that may un

  1. Some Brain Cancer Patients Have Radiation Options: Study

    Science.gov (United States)

    ... The report was published July 26 in the Journal of the American Medical Association . In the past, whole brain radiation was ... New Hyde Park, N.Y.; July 26, 2016, Journal of the American Medical Association HealthDay Copyright (c) 2016 HealthDay . All rights ...

  2. Integrated undergraduate research experience for the study of brain injury.

    Science.gov (United States)

    Barnes, Clifford L; Sierra, Michelle; Delay, Eugene R

    2003-01-01

    We developed a series of hands-on laboratory exercises on "Brain Injury" designed around several pedagogical goals that included the development of: 1) knowledge of the scientific method, 2) student problem solving skills by testing cause and effect relationships, 3) student analytical and critical thinking skills by evaluating and interpreting data, identifying alternative explanations for data, and identifying confounding variables, and 4) student writing skills by reporting their findings in manuscript form. Students, facilitated by the instructor, developed a testable hypothesis on short-term effects of brain injury by analyzing lesion size and astrocytic activity. Four sequential laboratory exercises were used to present and practice ablation techniques, histological processing, microscopic visualization and image-capture, and computer aided image analysis. This exercise culminated in a laboratory report that mimicked a research article. The effectiveness of the laboratory sequence was assessed by measuring the acquisition of 1) content on anatomical, physiological, and cellular responses of the brain to traumatic brain injury, and 2) laboratory skills and methods of data-collection and analysis using surgical procedures, histology, microscopy, and image analysis. Post-course test scores, significantly greater than pre-course test scores and greater than scores from a similar but unstructured laboratory class, indicated that this hands-on approach to teaching an undergraduate research laboratory was successful. Potential variations in the integrated laboratory exercise, including multidisciplinary collaborations, are also noted.

  3. Glycosylated Sertraline-Loaded Liposomes for Brain Targeting: QbD Study of Formulation Variabilities and Brain Transport.

    Science.gov (United States)

    Harbi, Ibrahim; Aljaeid, Bader; El-Say, Khalid M; Zidan, Ahmed S

    2016-12-01

    Effectiveness of CNS-acting drugs depends on the localization, targeting, and capacity to be transported through the blood-brain barrier (BBB) which can be achieved by designing brain-targeting delivery vectors. Hence, the objective of this study was to screen the formulation and process variables affecting the performance of sertraline (Ser-HCl)-loaded pegylated and glycosylated liposomes. The prepared vectors were characterized for Ser-HCl entrapment, size, surface charge, release behavior, and in vitro transport through the BBB. Furthermore, the compatibility among liposomal components was assessed using SEM, FTIR, and DSC analysis. Through a thorough screening study, enhancement of Ser-HCl entrapment, nanosized liposomes with low skewness, maximized stability, and controlled drug leakage were attained. The solid-state characterization revealed remarkable interaction between Ser-HCl and the charging agent to determine drug entrapment and leakage. Moreover, results of liposomal transport through mouse brain endothelialpolyoma cells demonstrated greater capacity of the proposed glycosylated liposomes to target the cerebellar due to its higher density of GLUT1 and higher glucose utilization. This transport capacity was confirmed by the inhibiting action of both cytochalasin B and phenobarbital. Using C6 glioma cells model, flow cytometry, time-lapse live cell imaging, and in vivo NIR fluorescence imaging demonstrated that optimized glycosylated liposomes can be transported through the BBB by classical endocytosis, as well as by specific transcytosis. In conclusion, the current study proposed a thorough screening of important formulation and process variabilities affecting brain-targeting liposomes for further scale-up processes.

  4. Introductory study of brain function data processing; No kino joho shori no sendo kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    An investigational study was conducted of the brain function aiming at developing an interface with the same function as humans have. In the study, the most up-to-date information/knowledge and future problems were examined on brain measurement, brain modeling, making a model an element, and the brain function data processing system. As to the brain measurement, the paper took up the multielectrode simultaneous measuring method and the optical multipoint measuring method as an invasive measuring method, and the functional magnetic resonance imaging, near-infrared spectroscopy, magneto-encephalography, and electro-encephalography as a non-invasive measuring method. Relating to the brain modeling, studies were made on senses of sight and smell, the movement control and the learning. As to making a model an element, how to make the modeled function a chip on silicone for example becomes the problem. Reported were two reports on making the sense of sight an element and one report on making the parallel dispersed processing mechanism of brain an element. About the brain function data processing system, three reports were made on the present situation, matters in question, and the future development of the system in the case of catching data processing as a system taking a step ahead from making the model an element. 250 refs., 74 figs., 11 tabs.

  5. Weight Gain following Pallidal Deep Brain Stimulation: A PET Study.

    Science.gov (United States)

    Sauleau, Paul; Drapier, Sophie; Duprez, Joan; Houvenaghel, Jean-François; Dondaine, Thibaut; Haegelen, Claire; Drapier, Dominique; Jannin, Pierre; Robert, Gabriel; Le Jeune, Florence; Vérin, Marc

    2016-01-01

    The mechanisms behind weight gain following deep brain stimulation (DBS) surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN) or the globus pallidus internus (GPi). Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET) and weight gain following GPi-DBS in patients with Parkinson's disease (PD). Body mass index was calculated and brain activity prospectively measured using 2-deoxy-2[18F]fluoro-D-glucose PET four months before and four months after the start of GPi-DBS in 19 PD patients. Dopaminergic medication was included in the analysis to control for its possible influence on brain metabolism. Body mass index increased significantly by 0.66 ± 1.3 kg/m2 (p = 0.040). There were correlations between weight gain and changes in brain metabolism in premotor areas, including the left and right superior gyri (Brodmann area, BA 6), left superior gyrus (BA 8), the dorsolateral prefrontal cortex (right middle gyrus, BAs 9 and 46), and the left and right somatosensory association cortices (BA 7). However, we found no correlation between weight gain and metabolic changes in limbic and associative areas. Additionally, there was a trend toward a correlation between reduced dyskinesia and weight gain (r = 0.428, p = 0.067). These findings suggest that, unlike STN-DBS, motor improvement is the major contributing factor for weight gain following GPi-DBS PD, confirming the motor selectivity of this target.

  6. A study of brain networks associated with swallowing using graph-theoretical approaches.

    Directory of Open Access Journals (Sweden)

    Bo Luan

    Full Text Available Functional connectivity between brain regions during swallowing tasks is still not well understood. Understanding these complex interactions is of great interest from both a scientific and a clinical perspective. In this study, functional magnetic resonance imaging (fMRI was utilized to study brain functional networks during voluntary saliva swallowing in twenty-two adult healthy subjects (all females, [Formula: see text] years of age. To construct these functional connections, we computed mean partial correlation matrices over ninety brain regions for each participant. Two regions were determined to be functionally connected if their correlation was above a certain threshold. These correlation matrices were then analyzed using graph-theoretical approaches. In particular, we considered several network measures for the whole brain and for swallowing-related brain regions. The results have shown that significant pairwise functional connections were, mostly, either local and intra-hemispheric or symmetrically inter-hemispheric. Furthermore, we showed that all human brain functional network, although varying in some degree, had typical small-world properties as compared to regular networks and random networks. These properties allow information transfer within the network at a relatively high efficiency. Swallowing-related brain regions also had higher values for some of the network measures in comparison to when these measures were calculated for the whole brain. The current results warrant further investigation of graph-theoretical approaches as a potential tool for understanding the neural basis of dysphagia.

  7. Microemulsion-based drug delivery system for transnasal delivery of Carbamazepine: preliminary brain-targeting study.

    Science.gov (United States)

    Patel, Rashmin Bharatbhai; Patel, Mrunali Rashmin; Bhatt, Kashyap K; Patel, Bharat G; Gaikwad, Rajiv V

    2016-01-01

    This study reports the development and evaluation of Carbamazepine (CMP)-loaded microemulsions (CMPME) for intranasal delivery in the treatment of epilepsy. The CMPME was prepared by the spontaneous emulsification method and characterized for physicochemical parameters. All formulations were radiolabeled with (99m)Tc (technetium) and biodistribution of CMP in the brain was investigated using Swiss albino rats. Brain scintigraphy imaging in rats was also performed to determine the uptake of the CMP into the brain. CMPME were found crystal clear and stable with average globule size of 34.11 ± 1.41 nm. (99m)Tc-labeled CMP solution (CMPS)/CMPME/CMP mucoadhesive microemulsion (CMPMME) were found to be stable and suitable for in vivo studies. Brain/blood ratio at all sampling points up to 8 h following intranasal administration of CMPMME compared to intravenous CMPME was found to be 2- to 3-fold higher signifying larger extent of distribution of the CMP in brain. Drug targeting efficiency and direct drug transport were found to be highest for CMPMME post-intranasal administration compared to intravenous CMP. Rat brain scintigraphy also demonstrated higher intranasal uptake of the CMP into the brain. This investigation demonstrates a prompt and larger extent of transport of CMP into the brain through intranasal CMPMME, which may prove beneficial for treatment of epilepsy.

  8. Clinicopathological pattern of brain tumors: A 3-year study in a tertiary care hospital in India

    Directory of Open Access Journals (Sweden)

    Sajeeb Mondal

    2016-01-01

    Full Text Available Background: Brain tumors are heterogeneous group of neoplasms, affecting different age groups. Although some studies have been published regarding pathological pattern of brain tumors from different countries of the world and also from India, comprehensive clinicopathological studies from Eastern India is lacking. Aims: The aim of this study was to observe recent incidence of different brain tumors and to study clinical and histopathological spectrum of brain tumors in Eastern India. Materials and Methods: The present study was a cross-sectional observational study involving 130 cases of brain tumors which were diagnosed during the 3-year study period (January 2010–December 2012. Data regarding clinical presentation and radiological features of all cases were collected from all patients. Histopathological diagnosis was correlated with clinical and radiological diagnosis. Results: We found 130 cases of brain tumor with a male preponderance. The cases were distributed in a wide age range from 4 years to 78 years with the mean age of 42.38 years. Most common tumor type in our study was neuroepithelial tumor (92 cases, 70.76%. Among the neuroepithelial tumors, most frequent subtype was astrocytic tumor (54 cases, 41.5%. The second most frequent brain tumor was meningioma (20 cases, 15.3%. We found higher incidence of oligodendroglial tumor (8.46% and medulloblastoma (7.69% in our series. Conclusion: Males are more predispose to brain tumors in comparison to females. Astrocytic tumors are most common subtype in Eastern India. However, the WHO Grade I neoplasms are more frequent brain tumors.

  9. Short-hairpin RNA-mediated Heat shock protein 90 gene silencing inhibits human breast cancer cell growth in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Keqiang [Department of General Surgery, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China); Li, Dan [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China); Pulli, Benjamin [Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, 185 Cambridge Street, Boston, MA 02114 (United States); Yu, Fei; Cai, Haidong; Yuan, Xueyu [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China); Zhang, Xiaoping, E-mail: zxpsibs@163.com [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China); Lv, Zhongwei, E-mail: heyixue163@163.com [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Hsp90 is over-expressed in human breast cancer. Black-Right-Pointing-Pointer The shRNA-mediated gene silencing of Hsp90 resulted in inhibition of cell growth. Black-Right-Pointing-Pointer Akt and NF-kB were down-regulation after transfection due to Hsp90 silencing. Black-Right-Pointing-Pointer The tumor growth ratio was decline due to Hsp90 silencing. Black-Right-Pointing-Pointer The PCNA expression was down-regulation due to Hsp90 silencing. -- Abstract: Hsp90 interacts with proteins that mediate signaling pathways involved in the regulation of essential processes such as proliferation, cell cycle control, angiogenesis and apoptosis. Hsp90 inhibition is therefore an attractive strategy for blocking abnormal pathways that are crucial for cancer cell growth. In the present study, the role of Hsp90 in human breast cancer MCF-7 cells was examined by stably silencing Hsp90 gene expression with an Hsp90-silencing vector (Hsp90-shRNA). RT-PCR and Western blot analyses showed that Hsp90-shRNA specifically and markedly down-regulated Hsp90 mRNA and protein expression. NF-kB and Akt protein levels were down-regulated in Hsp90-shRNA transfected cells, indicating that Hsp90 knockout caused a reduction of survival factors and induced apoptosis. Treatment with Hsp90-shRNA significantly increased apoptotic cell death and caused cell cycle arrest in the G1/S phase in MCF-7 cells, as shown by flow cytometry. Silencing of Hsp90 also reduced cell viability, as determined by MTT assay. In vivo experiments showed that MCF-7 cells stably transfected with Hsp90-shRNA grew slowly in nude mice as compared with control groups. In summary, the Hsp90-shRNA specifically silenced the Hsp90 gene, and inhibited MCF-7 cell growth in vitro and in vivo. Possible molecular mechanisms underlying the effects of Hsp90-shRNA include the degradation of Hsp90 breast cancer-related client proteins, the inhibition of survival signals and the upregulation of apoptotic

  10. Enhancement of Brain Functions During Aging Through Various Exercises: a Review Study

    Directory of Open Access Journals (Sweden)

    Bijay Kumar Bhagat

    2016-09-01

    Full Text Available Introduction: Decline of brain and mental functions with aging is a natural biological phenomenon. Scientists have engaged themselves to find out the different ways to protect degeneration and enhance brain functions. Regular exercise is one of the potential area. However, there are controversial and inconclusive results which create further interest of research. Aim: To review scientific literature related to exercise effect on brain and mental function during aging. Methods: Searches were conducted through electronic databases- PubMed, Medline, Springer link, Elsevier, and Google Scholar. The searching terms were: brain function (brain function or cognition or memory or processing speed or learning or executive function and physical exercise (physical exercise or exercise or stretching exercise or strength exercise. Initial search were 11 review studies and 57 randomized control trials. The current study selected 03 review and 08 randomized control trials studies after fulfillment of its requirement. Findings: Long term (>24 weeks combination exercise (aerobic, strength and stretching training can improve memory functions and processing speed in elderly people. Aerobic exercise training and strength training together can contribute to the improvement of episodic memory, executive functions and processing speed in healthy elderly people. Memory can be enhanced through aerobic exercise training and also by doing strength exercise training in healthy older adults. Interpretations: Changes in different brain and mental functions may be occurred due to structural and functional variations. The structural changes may include change in the volume of hippocampus, neurogenesis, angiogenesis, and so on. The physiological variations can include brain plasticity, increase in brain-derived neurotrophic factor (BDNF, enhancement of Default Mode Network (DMN, increase the activity of proteasome and neprilysin. Conclusions: Aging brain and mental functions

  11. Brain Functional Connectivity in MS: An EEG-NIRS Study

    Science.gov (United States)

    2015-10-01

    oxygen- based ( near -infrared spectroscopy (NIRS), functional MRI (fMRI)) signals, and to use the results to help optimize BOLD fMRI analyses of brain...2. Keywords BOLD – blood oxygen level dependent EEG – electroencephalography NIRS – near -infrared spectroscopy fMRI – functional MRI MS...INTRODUCTION TO ELECTROENCEPHALOGRAPHY AND NEAR -INFRARED SPECTROSCOPY NEUROIMAGING MEASUREMENT AND ANALYSIS P.40LO GlACO~lETTT 1. COURSE O VERVIEW T he

  12. STUDY OF REGIONAL STABILITY OF ECD DISTRIBUTION IN NORMAL BRAIN

    Institute of Scientific and Technical Information of China (English)

    李培勇; 陈刚; 朱承谟

    2001-01-01

    Objective To evaluate in vivo stability of ethylenedylbis cysteine diethylester ( ECD ) brain SPECT. Methods Each of13 normal volunteers (31.2±11.8 years) has12 dynamic SPECT scans acquired in 60min 1h after an injection of 99mTc-ECD using a triple headed gamma camera equipped with ultra high resolution fan beam collimators. Average counts per pixel were measured from frontal, temporal, parietal, occipital regions, cerebellum, basal ganglia, thalamus and white matter. Regional ECD clearance rates, regional gray-to-white matter (G/W) ratios and the change of the G /W ratio were calculated. Results The average ECD clearance rate was 4.2%/h, ranged from 3.03%/h to 5.41%/h corresponding to white matter and occipital. There was no significant difference between regional ECD clearance rates. Regional G/W ratio was between 1.27 to 1.75. The G /W ratio of temporal lobe was lower than the occipital (P<0.05). The change of regional G /W ratio with time is slow. Cbnclusion Regional ECD distribution is stable in normal brain. ECD clearance from brain is slow and no significant regional difference.

  13. A pilot study of accelerated irradiation for brain metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Michinao; Tokuuye, Koichi; Akine, Yasuyuki; Akimoto, Tetsuo; Ogino, Takashi; Tsukiyama, Iwao; Ono, Ryosuke; Egawa, Sunao (National Cancer Center, Tokyo (Japan). Hospital)

    1992-12-01

    Twenty-eight patients with brain metastases received brain radiotherapy with a total dose of 48 Gy, at 2 Gy per fraction, twice a day with a minimum interfractional period of 4 hours, and 5 days per week. This was intended to shorten the treatment period without increasing the morbidity, since most of these patients had a limited survival expectancy. Twenty-six of the 28 patients completed the radiotherapy. Three of the 26 patients experienced nausea and/or vomiting during the treatment. Radiotherapy was interrupted in two patients: one developed hemiplegia, and the other somnolence, both of which resulted from the progressive intracerebral disease. This radiotherapy regimen appears to be comparable to the conventional scheme in alleviation of symptoms. No patient needed interruption of the planned course of treatment because of acute irradiation toxicity. Based on these results, a multi-institutional randomized trial has been initiated to compare the twice-a-day and once-a-day radiotherapy schemes on patients with brain metastases. (author).

  14. A study of brain MRI findings in children with epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Sachiko; Sumida, Sawako; Muto, Ayako; Osawa, Makiko; Ono, Yuko [Tokyo Women' s Medical Coll. (Japan); Uchida, Moriyasu; Maruyama, Hiroshi

    2000-06-01

    Magnetic resonance imaging in the brain was performed in 293 patients with childhood-onset (<15 y.o.) epilepsy who had been classified into 4 groups, idiopathic localization-related epilepsy (ILRE), 78 patients; idiopathic generalized epilepsy (IGE), 116 patients; symptomatic localization-related epilepsy (SLRE), 68 patients and symptomatic generalized epilepsy (SGE), 31 patients, with the Classification of Epilepsies and Epileptic Syndrome (1989 International League Against Epilepsy). The examination was performed with a 1.5 T magnet. One hundred twenty-five patients (42.7%) showed abnormal findings, and the incidence in each group was as follows: Idiopathic epilepsy: The rate of abnormal findings in the ILRE and IGE groups was 21.8% and 20.7%, respectively. Most of the abnormal findings were secondary changes, such as diffuse or localized brain atrophy. Of the congenital abnormalities, the main finding was arachnoid cyst. Symptomatic epilepsy: The rate of abnormality in the SLRE patients was 88.2%, and 85% of the findings were secondary changes, i.e., brain atrophy, or degeneration of the white matter. In the SGE group, the rate was 77.4%, with an almost equal percentage of congenital and secondary changes. Of 255 patients who were examined by electroencephalography (EEG) on the same day as MRI, about 50% showed a correlation between the EEG records and the MRI abnormalities. However, only 8 patients showed a correlation in localization between the EEG and MRI abnormalities. (author)

  15. A DTI-Based Template-Free Cortical Connectome Study of Brain Maturation

    Science.gov (United States)

    Tymofiyeva, Olga; Hess, Christopher P.; Ziv, Etay; Lee, Patricia N.; Glass, Hannah C.; Ferriero, Donna M.; Barkovich, A. James; Xu, Duan

    2013-01-01

    Improved understanding of how the human brain is “wired” on a macroscale may now be possible due to the emerging field of MRI connectomics. However, mapping the rapidly developing infant brain networks poses challenges. In this study, we applied an automated template-free “baby connectome” framework using diffusion MRI to non-invasively map the structural brain networks in subjects of different ages, including premature neonates, term-born neonates, six-month-old infants, and adults. We observed increasing brain network integration and decreasing segregation with age in term-born subjects. We also explored how the equal area nodes can be grouped into modules without any prior anatomical information – an important step toward a fully network-driven registration and analysis of brain connectivity. PMID:23675475

  16. Pre and post betahistine therapy 99m Tc - HMPAO brain spect studies in patients with vertigo.

    Directory of Open Access Journals (Sweden)

    Krishna B

    2000-07-01

    Full Text Available Vertebro basilar insufficiency (VBI is a well known cause of vertigo. Brain Single Photon Emission Computed Tomography (SPECT is an important diagnostic tool to detect and to quantitate the perfusion abnormalities in different areas of the brain. Effect of an antivertigo drug Betahistine on improving the hypoperfusion in different areas of the brain in vertigo patients was studied using brain SPECT. Betahistine at a dose of 16 mg three times daily was shown to improve perfusion in the hypoperfused areas of the brain resulting in relief from symptoms of vertigo. The cerebellar region, which is the most important area involved in vertigo patients with vascular pathology, showed almost complete normalisation of perfusion following Betahistine therapy.

  17. Recent studies of iron deficiency during brain development in nonhuman primates.

    Science.gov (United States)

    Golub, Mari S

    2010-01-01

    Recent studies of the effects of developmental iron deficiency (ID) and iron deficiency anemia in nonhuman primates have provided new insights into this widespread and well-recognized human nutritional deficiency. The rhesus monkey was the animal model in these experiments, which used extensive hematological and behavioral evaluations in addition to noninvasive brain measures. Two important findings were as follows: 1) different behavioral consequences depending on the timing of ID relative to brain developmental stages and 2) the potential for long-lasting changes in brain iron regulatory systems. Further work in this model, including integration with studies in humans and in laboratory rodents, is ongoing.

  18. Brain Basics

    Medline Plus

    Full Text Available ... have been linked to many mental disorders, including autism , obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain ... studies show that brain growth in children with autism appears to peak early. And as they grow ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ... depression experience when starting treatment. Gene Studies Advanced technologies are also making it faster, easier, and more ...

  20. Exosomes in the Diseased Brain: First Insights from In vivo Studies

    Science.gov (United States)

    Levy, Efrat

    2017-01-01

    Extracellular vesicles (EVs) are nanoscale size vesicles secreted by cells and are important mediators of intercellular communication and genetic exchange. Exosomes, EVs generated in endosomal multivesicular bodies, have been the focus of numerous publications as they have emerged as clinically valuable markers of disease states. Exosomes have been mostly studied from conditioned culture media and body fluids, with the difficulty of isolating exosomes from tissues having delayed their study in vivo. The implementation of a method designed to isolate exosomes from tissues, however, has yielded the first insights into characteristics of exosomes in the brain. It has been observed that brain exosomes from murine models of neurodegenerative diseases and human postmortem brains tend to mirror the protein content of the cells of origin, and interestingly, they are enriched with toxic proteins. Whether this enrichment with neurotoxic proteins is beneficial by relieving neurons of accumulated toxic material or detrimental to the brain by propagating pathogenicity throughout the brain remains to be answered. Here is summarized the first group of studies describing exosomes isolated from brain, results that demonstrate that exosomes in vivo reflect complex multicellular pathogenic processes in neurodegenerative disorders and the brain's response to injury and damage.

  1. Cross-frequency coupling of brain oscillations in studying motivation and emotion.

    Science.gov (United States)

    Schutter, Dennis J L G; Knyazev, Gennady G

    2012-03-01

    Research has shown that brain functions are realized by simultaneous oscillations in various frequency bands. In addition to examining oscillations in pre-specified bands, interactions and relations between the different frequency bandwidths is another important aspect that needs to be considered in unraveling the workings of the human brain and its functions. In this review we provide evidence that studying interdependencies between brain oscillations may be a valuable approach to study the electrophysiological processes associated with motivation and emotional states. Studies will be presented showing that amplitude-amplitude coupling between delta-alpha and delta-beta oscillations varies as a function of state anxiety and approach-avoidance-related motivation, and that changes in the association between delta-beta oscillations can be observed following successful psychotherapy. Together these studies suggest that cross-frequency coupling of brain oscillations may contribute to expanding our understanding of the neural processes underlying motivation and emotion.

  2. Epidemiology, Severity Classification, and Outcome of Moderate and Severe Traumatic Brain Injury: A Prospective Multicenter Study

    NARCIS (Netherlands)

    T.M.J.C. Andriessen; J. Horn; G. Franschman; J. van der Naalt; I. Haitsma; B. Jacobs; E.W. Steyerberg; P.E. Vos

    2011-01-01

    Changes in the demographics, approach, and treatment of traumatic brain injury (TBI) patients require regular evaluation of epidemiological profiles, injury severity classification, and outcomes. This prospective multicenter study provides detailed information on TBI-related variables of 508 moderat

  3. Webinar Presentation: Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment

    Science.gov (United States)

    This presentation, Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series: Interdisciplinary Approaches to Neurodevelopment.

  4. Epidemiology, severity classification, and outcome of moderate and severe traumatic brain injury: a prospective multicenter study

    NARCIS (Netherlands)

    Andriessen, T.M.J.C.; Horn, J.; Franschman, G.; Naalt, J. van der; Haitsma, I.; Jacobs, B.; Steyerberg, E.W.; Vos, P.E.

    2011-01-01

    Changes in the demographics, approach, and treatment of traumatic brain injury (TBI) patients require regular evaluation of epidemiological profiles, injury severity classification, and outcomes. This prospective multicenter study provides detailed information on TBI-related variables of 508 moderat

  5. Epidemiology, Severity Classification, and Outcome of Moderate and Severe Traumatic Brain Injury : A Prospective Multicenter Study

    NARCIS (Netherlands)

    Andriessen, Teuntje M. J. C.; Horn, Janneke; Franschman, Gaby; van der Naalt, Joukje; Haitsma, Iain; Jacobs, Bram; Steyerberg, Ewout W.; Vos, Pieter E.

    2011-01-01

    Changes in the demographics, approach, and treatment of traumatic brain injury (TBI) patients require regular evaluation of epidemiological profiles, injury severity classification, and outcomes. This prospective multicenter study provides detailed information on TBI-related variables of 508 moderat

  6. Assessment of SPM in perfusion brain SPECT studies. A numerical simulation study using bootstrap resampling methods.

    Science.gov (United States)

    Pareto, Deborah; Aguiar, Pablo; Pavía, Javier; Gispert, Juan Domingo; Cot, Albert; Falcón, Carles; Benabarre, Antoni; Lomeña, Francisco; Vieta, Eduard; Ros, Domènec

    2008-07-01

    Statistical parametric mapping (SPM) has become the technique of choice to statistically evaluate positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and single photon emission computed tomography (SPECT) functional brain studies. Nevertheless, only a few methodological studies have been carried out to assess the performance of SPM in SPECT. The aim of this paper was to study the performance of SPM in detecting changes in regional cerebral blood flow (rCBF) in hypo- and hyperperfused areas in brain SPECT studies. The paper seeks to determine the relationship between the group size and the rCBF changes, and the influence of the correction for degradations. The assessment was carried out using simulated brain SPECT studies. Projections were obtained with Monte Carlo techniques, and a fan-beam collimator was considered in the simulation process. Reconstruction was performed by using the ordered subsets expectation maximization (OSEM) algorithm with and without compensation for attenuation, scattering, and spatial variant collimator response. Significance probability maps were obtained with SPM2 by using a one-tailed two-sample t-test. A bootstrap resampling approach was used to determine the sample size for SPM to detect the between-group differences. Our findings show that the correction for degradations results in a diminution of the sample size, which is more significant for small regions and low-activation factors. Differences in sample size were found between hypo- and hyperperfusion. These differences were larger for small regions and low-activation factors, and when no corrections were included in the reconstruction algorithm.

  7. Immunohistochemical study of IOT-10 natural killer cells in brain metastases.

    Science.gov (United States)

    Vaquero, J; Coca, S; Escandón, J; Magallón, R; Martínez, R

    1990-01-01

    The presence of NK-cells in a series of 40 metastatic brain tumours has been studied by means of the monoclonal antibody IOT-10. There appeared IOT-10 NK-cells in all tumours studied, but in most cases these cells represented less than 10% of the tumour infiltrating lymphocytes (TIL). In the present series, the obtained data suggest that the number of NK-cells in brain metastases can be influenced by other factors than the mere quantity of TIL.

  8. Communication and the primate brain: insights from neuroimaging studies in humans, chimpanzees and macaques.

    Science.gov (United States)

    Wilson, Benjamin; Petkov, Christopher I

    2011-04-01

    Considerable knowledge is available on the neural substrates for speech and language from brain-imaging studies in humans, but until recently there was a lack of data for comparison from other animal species on the evolutionarily conserved brain regions that process species-specific communication signals. To obtain new insights into the relationship of the substrates for communication in primates, we compared the results from several neuroimaging studies in humans with those that have recently been obtained from macaque monkeys and chimpanzees. The recent work in humans challenges the longstanding notion of highly localized speech areas. As a result, the brain regions that have been identified in humans for speech and nonlinguistic voice processing show a striking general correspondence to how the brains of other primates analyze species-specific vocalizations or information in the voice, such as voice identity. The comparative neuroimaging work has begun to clarify evolutionary relationships in brain function, supporting the notion that the brain regions that process communication signals in the human brain arose from a precursor network of regions that is present in nonhuman primates and is used for processing species-specific vocalizations. We conclude by considering how the stage now seems to be set for comparative neurobiology to characterize the ancestral state of the network that evolved in humans to support language.

  9. Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study

    Directory of Open Access Journals (Sweden)

    Rafael Simas

    2012-01-01

    Full Text Available OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30%, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70% reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage

  10. Prolonged repeated acupuncture stimulation induces habituation effects in pain-related brain areas: an FMRI study.

    Science.gov (United States)

    Li, Chuanfu; Yang, Jun; Park, Kyungmo; Wu, Hongli; Hu, Sheng; Zhang, Wei; Bu, Junjie; Xu, Chunsheng; Qiu, Bensheng; Zhang, Xiaochu

    2014-01-01

    Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36). Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM) analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA) to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia.

  11. Brain Activity Associated with Emoticons: An fMRI Study

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe that brain activities associated with emoticons by using fMRI. In communication over a computer network, we use abstract faces such as computer graphics (CG) avatars and emoticons. These faces convey users' emotions and enrich their communications. However, the manner in which these faces influence the mental process is as yet unknown. The human brain may perceive the abstract face in an entirely different manner, depending on its level of reality. We conducted an experiment using fMRI in order to investigate the effects of emoticons. The results show that right inferior frontal gyrus, which associated with nonverbal communication, is activated by emoticons. Since the emoticons were created to reflect the real human facial expressions as accurately as possible, we believed that they would activate the right fusiform gyrus. However, this region was not found to be activated during the experiment. This finding is useful in understanding how abstract faces affect our behaviors and decision-making in communication over a computer network.

  12. [Paradise lost - Reflexion of preterm birth from the perspective after a brain injury. A case study].

    Science.gov (United States)

    Cignacco, Eva; Zuñiga, Franziska; Kurth, Elisabeth

    2011-04-01

    This case study describes the history of an older person, born in 1942 preterminally, who suffered from a brain injury in 2005. Problems in rehabilitation elicited the search for a new meaning in life. In analysing and interpreting the brain injury, preterm birth played a crucial role. The theme of lifelong compensation of deficits, caused by preterm birth, gained new importance. The consequences of brain injury left unsuccessful his former modes of compensation. He was confronted with finding new strategies in order to counterbalance the growing decompensation. This report is based on and was developed through respect for the principles of user involvement in research.

  13. Cohort Study of Multiple Brain Lesions in Sport Divers: Role of a Patent Foramen Ovale

    Science.gov (United States)

    Knauth, Michael; Ries, Stefan; Pohimann, Stefan; Kerby, Tina; Forstring, Michael; Daffertshofer, Michael; Hennerici,Michael; Sartor, Klaus

    1997-01-01

    To investigate the role of a patent foramen ovale in the pathogenesis of multiple brain lesions acquired by sport divers in the absence of reported decompression symptoms. Design: Prospective double blind cohort study. . Setting Diving clubs around Heidelberg and departments of neuroradiology and neurology. Subjects: 87 sport divers with a minimum of 160 scuba dives (dives with self contained underwater breathing apparatus). Main outcome measures: Presence of multiple brain lesions visualised by cranial magnetic resonance imaging and presence and size of patent foramen ovale as documented by echocontrast transcranial Doppler ultrasonograhy. Results: 25 subjects were found to have a right-to-left shunt, 13 with a patent foramen ovale of high haemodynamic relevance. A total of 41 brain lesions were detected in 11 divers. There were seven brain lesions in seven divers without a right-to-left shunt and 34 lesions in four divers with a right-to-left shunt Multiple brain lesions occurred exclusively in three divers with a large patent foramen ovale (P=0.004). Conclusions: Multiple brain lesions in sport divers were associated with presence of a large patent foramen ovale. This association suggests paradoxical gas embolism as the pathological mechanism. A patent foramen ovale of high haemodynamic relevance seems to be an important risk factor for developing multiple brain lesions in sport divers.

  14. Experimental study on the establishment and maintenance of brain death model with pigs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shuijun; SHI Jihua; ZHAI Wenlong; SONG Yan; CHEN Shi

    2007-01-01

    It remains controversial that after the transplantation of using grafts from brain-dead donors,organs injury and rejection can influence the effects of transplantation.This study sought to explore methods of establishing a stable brain death(BD)model using Bama mini pigs and to maintain the brain-dead state for a comparatively long period to provide a model for investigating changes in brain death.Sixteen anesthetized Bama mini pigs were randomized into a control group(n=5)and a BD group(n=11).Intracranial pressure (ICP)was increased in a modified,slow,and intermittent way to establish BD.Respiration and circulation were sustained during the brain-dead state.Hemodynamic changes were monitored during the experiment.In the BD group,10 pigs met the requirements for brain death and 1 died of cardiopulmonary complications following an increase in ICP.Brain death was maintained for more than 48 hours with artificial life support.During the experiment,the heart rate and blood pressure showed characteristic changes due to increased ICP.Prior to BD being established,a"tic reaction"inevitably occurred.We used an improved method of increasing ICP to establish a stable BD model.The BD state could be maintained for more than 48 hours with effective respiratory and circulatory support.Disappearance of the tic reaction was considered to be one of the verified indexes for BD via encephalic pressure increase.

  15. [Molecular cytogenetic methods for studying interphase chromosomes in human brain cells].

    Science.gov (United States)

    Iurov, I Iu; Vorsanova, S G; Solov'ev, I V; Iurov, Iu B

    2010-09-01

    One of the main genetic factors determining the functional activity of the genome in somatic cells, including brain nerve cells, is the spatial organization of chromosomes in the interphase nucleus. For a long time, no studies of human brain cells were carried out until high-resolution methods of molecular cytogenetics were developed to analyze interphase chromosomes in nondividing somatic cells. The purpose of the present work was to assess the potential of high-resolution methods of interphase molecular cytogenetics for studying chromosomes and the nuclear organization in postmitotic brain cells. A high efficiency was shown by such methods as multiprobe and quantitative fluorescence in situ hybridization (Multiprobe FISH and QFISH), ImmunoMFISH (analysis of the chromosome organization in different types of brain cells), and interphase chromosome-specific multicolor banding (ICS-MCB). These approaches allowed studying the nuclear organization depending on the gene composition and types of repetitive DNA of specific chromosome regions in certain types of brain cells (in neurons and glial cells, in particular). The present work demonstrates a high potential of interphase molecular cytogenetics for studying the structural and functional organizations of the cell nucleus in highly differentiated nerve cells. Analysis of interphase chromosomes of brain cells in the normal and pathological states can be considered as a promising line of research in modern molecular cytogenetics and cell neurobiology, i. e., molecular neurocytogenetics.

  16. Development of luciferase tagged brain tumour models in mice for chemotherapy intervention studies.

    Science.gov (United States)

    Kemper, E M; Leenders, W; Küsters, B; Lyons, S; Buckle, T; Heerschap, A; Boogerd, W; Beijnen, J H; van Tellingen, O

    2006-12-01

    The blood-brain barrier (BBB) is considered one of the major causes for the low efficacy of cytotoxic compounds against primary brain tumours. The aim of this study was to develop intracranial tumour models in mice featuring intact or locally disrupted BBB properties, which can be used in testing chemotherapy against brain tumours. These tumours were established by intracranial injection of suspensions of different tumour cell lines. All cell lines had been transfected with luciferase to allow non-invasive imaging of tumour development using a super-cooled CCD-camera. Following their implantation, tumours developed which displayed the infiltrative, invasive or expansive growth patterns that are also found in primary brain cancer or brain metastases. Contrast-enhanced magnetic resonance imaging showed that the Mel57, K1735Br2 and RG-2 lesions grow without disruption of the BBB, whereas the BBB was leaky in the U87MG and VEGF-A-transfected Mel57 lesions. This was confirmed by immunohistochemistry. Bioluminescence measurements allowed the visualisation of tumour burden already within 4 days after injection of the tumour cells. The applicability of our models for performing efficacy studies was demonstrated in an experiment using temozolomide as study drug. In conclusion, we have developed experimental brain tumour models with partly disrupted, or completely intact BBB properties. In vivo imaging by luciferase allows convenient follow-up of tumour growth and these models will be useful for chemotherapeutic intervention studies.

  17. Disrupted small-world brain networks in moderate Alzheimer's disease: a resting-state FMRI study.

    Directory of Open Access Journals (Sweden)

    Xiaohu Zhao

    Full Text Available The small-world organization has been hypothesized to reflect a balance between local processing and global integration in the human brain. Previous multimodal imaging studies have consistently demonstrated that the topological architecture of the brain network is disrupted in Alzheimer's disease (AD. However, these studies have reported inconsistent results regarding the topological properties of brain alterations in AD. One potential explanation for these inconsistent results lies with the diverse homogeneity and distinct progressive stages of the AD involved in these studies, which are thought to be critical factors that might affect the results. We investigated the topological properties of brain functional networks derived from resting functional magnetic resonance imaging (fMRI of carefully selected moderate AD patients and normal controls (NCs. Our results showed that the topological properties were found to be disrupted in AD patients, which showing increased local efficiency but decreased global efficiency. We found that the altered brain regions are mainly located in the default mode network, the temporal lobe and certain subcortical regions that are closely associated with the neuropathological changes in AD. Of note, our exploratory study revealed that the ApoE genotype modulates brain network properties, especially in AD patients.

  18. Erythropoietin in traumatic brain injury: study protocol for a randomised controlled trial.

    LENUS (Irish Health Repository)

    Nichol, Alistair

    2015-02-08

    Traumatic brain injury is a leading cause of death and disability worldwide. Laboratory and clinical studies demonstrate a possible beneficial effect of erythropoietin in improving outcomes in the traumatic brain injury cohort. However, there are concerns regarding the association of erythropoietin and thrombosis in the critically ill. A large-scale, multi-centre, blinded, parallel-group, placebo-controlled, randomised trial is currently underway to address this hypothesis.

  19. Circulating and Brain BDNF Levels in Stroke Rats. Relevance to Clinical Studies

    OpenAIRE

    Yannick Béjot; Claude Mossiat; Maurice Giroud; Anne Prigent-Tessier; Christine Marie

    2011-01-01

    BACKGROUND: Whereas brain-derived neurotrophic factor (BDNF) levels are measured in the brain in animal models of stroke, neurotrophin levels in stroke patients are measured in plasma or serum samples. The present study was designed to investigate the meaning of circulating BDNF levels in stroke patients. METHODS AND RESULTS: Unilateral ischemic stroke was induced in rats by the injection of various numbers of microspheres into the carotid circulation in order to mimic the different degrees o...

  20. Cohort study of multiple brain lesions in sport divers: role of a patent foramen ovale.

    OpenAIRE

    1997-01-01

    OBJECTIVE: To investigate the role of a patient foramen ovale in the pathogenesis of multiple brain lesions acquired by sport divers in the absence of reported decompression symptoms. DESIGN: Prospective double blind cohort study. SETTING: Diving clubs around Heidelberg and departments of neuroradiology and neurology. SUBJECTS: 87 sport divers with a minimum of 160 scuba dives (dives with self contained underwater breathing apparatus). MAIN OUTCOME MEASURES: Presence of multiple brain lesions...

  1. LDA-SVM-based EGFR mutation model for NSCLC brain metastases: an observational study.

    Science.gov (United States)

    Hu, Nan; Wang, Ge; Wu, Yu-Hao; Chen, Shi-Feng; Liu, Guo-Dong; Chen, Chuan; Wang, Dong; He, Zhong-Shi; Yang, Xue-Qin; He, Yong; Xiao, Hua-Liang; Huang, Ding-De; Xiong, Kun-Lin; Wu, Yan; Huang, Ming; Yang, Zhen-Zhou

    2015-02-01

    Epidermal growth factor receptor (EGFR) activating mutations are a predictor of tyrosine kinase inhibitor effectiveness in the treatment of non-small-cell lung cancer (NSCLC). The objective of this study is to build a model for predicting the EGFR mutation status of brain metastasis in patients with NSCLC. Observation and model set-up. This study was conducted between January 2003 and December 2011 in 6 medical centers in Southwest China. The study included 31 NSCLC patients with brain metastases. Eligibility requirements were histological proof of NSCLC, as well as sufficient quantity of paraffin-embedded lung and brain metastases specimens for EGFR mutation detection. The linear discriminant analysis (LDA) method was used for analyzing the dimensional reduction of clinical features, and a support vector machine (SVM) algorithm was employed to generate an EGFR mutation model for NSCLC brain metastases. Training-testing-validation (3 : 1 : 1) processes were applied to find the best fit in 12 patients (validation test set) with NSCLC and brain metastases treated with a tyrosine kinase inhibitor and whole-brain radiotherapy. Primary and secondary outcome measures: EGFR mutation analysis in patients with NSCLC and brain metastases and the development of a LDA-SVM-based EGFR mutation model for NSCLC brain metastases patients. EGFR mutation discordance between the primary lung tumor and brain metastases was found in 5 patients. Using LDA, 13 clinical features were transformed into 9 characteristics, and 3 were selected as primary vectors. The EGFR mutation model constructed with SVM algorithms had an accuracy, sensitivity, and specificity for determining the mutation status of brain metastases of 0.879, 0.886, and 0.875, respectively. Furthermore, the replicability of our model was confirmed by testing 100 random combinations of input values. The LDA-SVM-based model developed in this study could predict the EGFR status of brain metastases in this small cohort of

  2. Multislice CT brain image registration for perfusion studies

    Science.gov (United States)

    Lin, Zhong Min; Pohlman, Scott; Chandra, Shalabh

    2002-04-01

    During the last several years perfusion CT techniques have been developed as an effective technique for clinically evaluating cerebral hemodynamics. Perfusion CT techniques are capable of measurings functional parameters such as tissue perfusion, blood flow, blood volume, and mean transit time and are commonly used to evaluate stroke patients. However, the quality of functional images of the brain frequently suffers from patient head motion. Because the time window for an effective treatment of stroke patient is narrow, a fast motion correction is required. The purpose of the paper is to present a fast and accurate registration technique for motion correction of multi-slice CT and to demonstrate the effects of the registration on perfusion calculation.

  3. A longitudinal study of structural brain network changes with normal aging

    Directory of Open Access Journals (Sweden)

    Kai eWu

    2013-04-01

    Full Text Available The aim of this study was to investigate age-related changes in the topological organization of structural brain networks by applying a longitudinal design over 6 years. Structural brain networks were derived from measurements of regional gray matter volume and were constructed in age-specific groups from baseline and follow-up scans. The structural brain networks showed economical small-world properties, providing high global and local efficiency for parallel information processing at low connection costs. In the analysis of the global network properties, the local and global efficiency of the baseline scan were significantly lower compared to the follow-up scan. Moreover, the annual rate of changes in local and global efficiency showed a positive and negative quadratic correlation with the baseline age, respectively; both curvilinear correlations peaked at approximately the age of 50. In the analysis of the regional nodal properties, significant negative correlations between the annual rate of changes in nodal strength and the baseline age were found in the brain regions primarily involved in the visual and motor/ control systems, whereas significant positive quadratic correlations were found in the brain regions predominately associated with the default-mode, attention, and memory systems. The results of the longitudinal study are consistent with the findings of our previous cross-sectional study: the structural brain networks develop into a fast distribution from young to middle age (approximately 50 years old and eventually became a fast localization in the old age. Our findings elucidate the network topology of structural brain networks and its longitudinal changes, thus enhancing the understanding of the underlying physiology of normal aging in the human brain.

  4. A Prospective Randomized Study of Brain Tissue Oxygen Pressure-Guided Management in Moderate and Severe Traumatic Brain Injury Patients

    Directory of Open Access Journals (Sweden)

    Chien-Min Lin

    2015-01-01

    Full Text Available The purpose of this study was to compare the effect of PbtO2-guided therapy with traditional intracranial pressure- (ICP- guided treatment on the management of cerebral variables, therapeutic interventions, survival rates, and neurological outcomes of moderate and severe traumatic brain injury (TBI patients. From 2009 to 2010, TBI patients with a Glasgow coma scale 20 mmHg, and 27 patients were treated with ICP-guided therapy (ICP 60 mmHg in the neurosurgical intensive care unit (NICU; demographic characteristics were similar across groups. The survival rate in the PbtO2-guided group was also significantly increased at 3 and 6 months after injury. Moreover, there was a significant correlation between the PbtO2 signal and Glasgow outcome scale-extended in patients from 1 to 6 months after injury. This finding demonstrates that therapy directed by PbtO2 monitoring is valuable for the treatment of patients with moderate and severe TBI and that increasing PaO2 to 150 mmHg may be efficacious for preventing cerebral hypoxic events after brain trauma.

  5. A study of the comparative anatomy of the brain of domestic ruminants using magnetic resonance imaging.

    Science.gov (United States)

    Schmidt, M J; Langen, N; Klumpp, S; Nasirimanesh, F; Shirvanchi, P; Ondreka, N; Kramer, M

    2012-01-01

    Although magnetic resonance imaging has been used to examine the brain of domestic ruminants, detailed information relating the precise anatomical features in these species is lacking. In this study the brain structures of calves (Bos taurus domesticus), sheep (Ovis aries), goats (Capra hircus) and a mesaticephalic dog (Canis lupis familiaris) were examined using T2-weighed Turbo Spin Echo sequences; three-dimensional models based on high-resolution gradient echo scans were used to identify brain sulci and gyri in two-dimensional images. The ruminant brains examined were similar in structure and organisation to those of other mammals but particular features included the deep depression of the insula and the pronounced gyri of the cortices, the dominant position of the visual (optic nerve, optic chiasm and rostral colliculus) and olfactory (olfactory bulb, olfactory tracts and piriform lobe) systems, and the relatively large size of the diencephalon.

  6. Spectrum of pediatric brain tumors in India: A multi-institutional study

    Directory of Open Access Journals (Sweden)

    Ayushi Jain

    2011-01-01

    Full Text Available Background : Till date there is no published multi-institutional data regarding the epidemiological profile of pediatric brain tumors in India. Aim : The present retrospective study analyses the histological spectrum of pediatric age group brain tumors in seven tertiary care hospitals in India. Material and Methods : Data regarding frequencies of various primary brain tumors (diagnosed according to the World Health Organization (WHO classification, in 3936 pediatric patients (<18 yrs of age, was collected from seven tertiary care hospitals in India.Results : The most common primary pediatric brain tumors were astrocytic tumors (34.7%, followed by medulloblastoma and supratentorial primitive neuro-ectodermal tumors (22.4%, craniopharyngiomas (10.2% and ependymal tumors (9.8%. The most common astrocytic tumor was pilocytic astrocytoma. In comparison to adults, oligodendrogliomas and lymphomas were rare in children. Conclusions : Our study is the first such report on the histological spectrum of brain tumors in children in India. Except for a slightly higher frequency of craniopharyngiomas, the histological profile of pediatric brain tumors in India is similar to that reported in the Western literature.

  7. Neurobiological origin of spurious brain morphological changes: A quantitative MRI study.

    Science.gov (United States)

    Lorio, Sara; Kherif, Ferath; Ruef, Anne; Melie-Garcia, Lester; Frackowiak, Richard; Ashburner, John; Helms, Gunther; Lutti, Antoine; Draganski, Bodgan

    2016-05-01

    The high gray-white matter contrast and spatial resolution provided by T1-weighted magnetic resonance imaging (MRI) has made it a widely used imaging protocol for computational anatomy studies of the brain. While the image intensity in T1-weighted images is predominantly driven by T1, other MRI parameters affect the image contrast, and hence brain morphological measures derived from the data. Because MRI parameters are correlates of different histological properties of brain tissue, this mixed contribution hampers the neurobiological interpretation of morphometry findings, an issue which remains largely ignored in the community. We acquired quantitative maps of the MRI parameters that determine signal intensities in T1-weighted images (R1 (=1/T1), R2 *, and PD) in a large cohort of healthy subjects (n = 120, aged 18-87 years). Synthetic T1-weighted images were calculated from these quantitative maps and used to extract morphometry features-gray matter volume and cortical thickness. We observed significant variations in morphometry measures obtained from synthetic images derived from different subsets of MRI parameters. We also detected a modulation of these variations by age. Our findings highlight the impact of microstructural properties of brain tissue-myelination, iron, and water content-on automated measures of brain morphology and show that microstructural tissue changes might lead to the detection of spurious morphological changes in computational anatomy studies. They motivate a review of previous morphological results obtained from standard anatomical MRI images and highlight the value of quantitative MRI data for the inference of microscopic tissue changes in the healthy and diseased brain. Hum Brain Mapp 37:1801-1815, 2016. © 2016 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.

  8. The fate of sounds in conductors' brains: an ERP study.

    Science.gov (United States)

    Nager, Wido; Kohlmetz, Christine; Altenmüller, Eckart; Rodriguez-Fornells, Antoni; Münte, Thomas F

    2003-06-01

    Professional music conductors are required to home in on a particular musician but at the same time have to monitor the entire orchestra. It was hypothesized that this unique experience should be reflected by superior auditory spatial processing. Event-related brain potentials were obtained, while conductors, professional pianists, and non-musicians listened to sequences of bandpass-filtered noise-bursts presented in random order from six speakers, three located in front and three to the right of the subjects. In different runs, subjects either attended the centermost or the most peripheral speaker in order to detect slightly deviant noise-bursts. For centrally located speakers, the ERPs showed a typical Nd attention effect for the relevant location with a steep decline for the neighboring speakers in all subject groups. For peripheral speakers, only the conductors showed attentional selectivity, while the Nd effect was of similar size for all three peripheral speakers in the other two groups. These ERP effects were paralleled by an enhanced behavioral selectivity in peripheral auditory space in conductors. Moreover, the pre-attentive monitoring of the entire auditory scene indexed by the mismatch negativity was superior in musicians compared to non-musicians. In conductors, the MMN was followed by a positivity suggesting an attention shift towards the deviant stimuli in this group only.

  9. Effects of Diet on Brain Plasticity in Animal and Human Studies: Mind the Gap

    Directory of Open Access Journals (Sweden)

    Tytus Murphy

    2014-01-01

    Full Text Available Dietary interventions have emerged as effective environmental inducers of brain plasticity. Among these dietary interventions, we here highlight the impact of caloric restriction (CR: a consistent reduction of total daily food intake, intermittent fasting (IF, every-other-day feeding, and diet supplementation with polyphenols and polyunsaturated fatty acids (PUFAs on markers of brain plasticity in animal studies. Moreover, we also discuss epidemiological and intervention studies reporting the effects of CR, IF and dietary polyphenols and PUFAs on learning, memory, and mood. In particular, we evaluate the gap in mechanistic understanding between recent findings from animal studies and those human studies reporting that these dietary factors can benefit cognition, mood, and anxiety, aging, and Alzheimer’s disease—with focus on the enhancement of structural and functional plasticity markers in the hippocampus, such as increased expression of neurotrophic factors, synaptic function and adult neurogenesis. Lastly, we discuss some of the obstacles to harnessing the promising effects of diet on brain plasticity in animal studies into effective recommendations and interventions to promote healthy brain function in humans. Together, these data reinforce the important translational concept that diet, a modifiable lifestyle factor, holds the ability to modulate brain health and function.

  10. Effects of diet on brain plasticity in animal and human studies: mind the gap.

    Science.gov (United States)

    Murphy, Tytus; Dias, Gisele Pereira; Thuret, Sandrine

    2014-01-01

    Dietary interventions have emerged as effective environmental inducers of brain plasticity. Among these dietary interventions, we here highlight the impact of caloric restriction (CR: a consistent reduction of total daily food intake), intermittent fasting (IF, every-other-day feeding), and diet supplementation with polyphenols and polyunsaturated fatty acids (PUFAs) on markers of brain plasticity in animal studies. Moreover, we also discuss epidemiological and intervention studies reporting the effects of CR, IF and dietary polyphenols and PUFAs on learning, memory, and mood. In particular, we evaluate the gap in mechanistic understanding between recent findings from animal studies and those human studies reporting that these dietary factors can benefit cognition, mood, and anxiety, aging, and Alzheimer's disease-with focus on the enhancement of structural and functional plasticity markers in the hippocampus, such as increased expression of neurotrophic factors, synaptic function and adult neurogenesis. Lastly, we discuss some of the obstacles to harnessing the promising effects of diet on brain plasticity in animal studies into effective recommendations and interventions to promote healthy brain function in humans. Together, these data reinforce the important translational concept that diet, a modifiable lifestyle factor, holds the ability to modulate brain health and function.

  11. Gene co-expression analysis identifies brain regions and cell types involved in migraine pathophysiology: a GWAS-based study using the Allen Human Brain Atlas.

    Science.gov (United States)

    Eising, Else; Huisman, Sjoerd M H; Mahfouz, Ahmed; Vijfhuizen, Lisanne S; Anttila, Verneri; Winsvold, Bendik S; Kurth, Tobias; Ikram, M Arfan; Freilinger, Tobias; Kaprio, Jaakko; Boomsma, Dorret I; van Duijn, Cornelia M; Järvelin, Marjo-Riitta R; Zwart, John-Anker; Quaye, Lydia; Strachan, David P; Kubisch, Christian; Dichgans, Martin; Davey Smith, George; Stefansson, Kari; Palotie, Aarno; Chasman, Daniel I; Ferrari, Michel D; Terwindt, Gisela M; de Vries, Boukje; Nyholt, Dale R; Lelieveldt, Boudewijn P F; van den Maagdenberg, Arn M J M; Reinders, Marcel J T

    2016-04-01

    Migraine is a common disabling neurovascular brain disorder typically characterised by attacks of severe headache and associated with autonomic and neurological symptoms. Migraine is caused by an interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified over a dozen genetic loci associated with migraine. Here, we integrated migraine GWAS data with high-resolution spatial gene expression data of normal adult brains from the Allen Human Brain Atlas to identify specific brain regions and molecular pathways that are possibly involved in migraine pathophysiology. To this end, we used two complementary methods. In GWAS data from 23,285 migraine cases and 95,425 controls, we first studied modules of co-expressed genes that were calculated based on human brain expression data for enrichment of genes that showed association with migraine. Enrichment of a migraine GWAS signal was found for five modules that suggest involvement in migraine pathophysiology of: (i) neurotransmission, protein catabolism and mitochondria in the cortex; (ii) transcription regulation in the cortex and cerebellum; and (iii) oligodendrocytes and mitochondria in subcortical areas. Second, we used the high-confidence genes from the migraine GWAS as a basis to construct local migraine-related co-expression gene networks. Signatures of all brain regions and pathways that were prominent in the first method also surfaced in the second method, thus providing support that these brain regions and pathways are indeed involved in migraine pathophysiology.

  12. Brain activity modification produced by a single radioelectric asymmetric brain stimulation pulse: a new tool for neuropsychiatric treatments. Preliminary fMRI study

    Directory of Open Access Journals (Sweden)

    Castagna A

    2011-10-01

    Full Text Available Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna1 1Department of Neuro-Psycho-Physio Pathology, Rinaldi Fontani Institute, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, Italy Purpose: Radioelectric asymmetric brain stimulation technology with its treatment protocols has shown efficacy in various psychiatric disorders. The aim of this work was to highlight the mechanisms by which these positive effects are achieved. The current study was conducted to determine whether a single 500-millisecond radioelectric asymmetric conveyor (REAC brain stimulation pulse (BSP, applied to the ear, can effect a modification of brain activity that is detectable using functional magnetic resonance imaging (fMRI. Methods: Ten healthy volunteers, six females and four males, underwent fMRI during a simple finger-tapping motor task before and after receiving a single 500-millisecond REAC-BSP. Results: The fMRI results indicate that the average variation in task-induced encephalic activation patterns is lower in subjects following the single REAC pulse. Conclusion: The current report demonstrates that a single REAC-BSP is sufficient to modulate brain activity in awake subjects, able to be measured using fMRI. These initial results open new perspectives into the understanding of the effects of weak and brief radio pulses upon brain activity, and provide the basis for further indepth studies using REAC-BSP and fMRI. Keywords: fMRI, brain stimulation, brain modulation, REAC, neuropsychiatric treatments

  13. Dynamics of the brain: Mathematical models and non-invasive experimental studies

    Science.gov (United States)

    Toronov, V.; Myllylä, T.; Kiviniemi, V.; Tuchin, V. V.

    2013-10-01

    Dynamics is an essential aspect of the brain function. In this article we review theoretical models of neural and haemodynamic processes in the human brain and experimental non-invasive techniques developed to study brain functions and to measure dynamic characteristics, such as neurodynamics, neurovascular coupling, haemodynamic changes due to brain activity and autoregulation, and cerebral metabolic rate of oxygen. We focus on emerging theoretical biophysical models and experimental functional neuroimaging results, obtained mostly by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). We also included our current results on the effects of blood pressure variations on cerebral haemodynamics and simultaneous measurements of fast processes in the brain by near-infrared spectroscopy and a very novel functional MRI technique called magnetic resonance encephalography. Based on a rapid progress in theoretical and experimental techniques and due to the growing computational capacities and combined use of rapidly improving and emerging neuroimaging techniques we anticipate during next decade great achievements in the overall knowledge of the human brain.

  14. Mechanism of case processing in the brain: an fMRI study.

    Directory of Open Access Journals (Sweden)

    Satoru Yokoyama

    Full Text Available In sentence comprehension research, the case system, which is one of the subsystems of the language processing system, has been assumed to play a crucial role in signifying relationships in sentences between noun phrases (NPs and other elements, such as verbs, prepositions, nouns, and tense. However, so far, less attention has been paid to the question of how cases are processed in our brain. To this end, the current study used fMRI and scanned the brain activity of 15 native English speakers during an English-case processing task. The results showed that, while the processing of all cases activates the left inferior frontal gyrus and posterior part of the middle temporal gyrus, genitive case processing activates these two regions more than nominative and accusative case processing. Since the effect of the difference in behavioral performance among these three cases is excluded from brain activation data, the observed different brain activations would be due to the different processing patterns among the cases, indicating that cases are processed differently in our brains. The different brain activations between genitive case processing and nominative/accusative case processing may be due to the difference in structural complexity between them.

  15. The Gini coefficient: a methodological pilot study to assess fetal brain development employing postmortem diffusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Viehweger, Adrian; Sorge, Ina; Hirsch, Wolfgang [University Hospital Leipzig, Department of Pediatric Radiology, Leipzig (Germany); Riffert, Till; Dhital, Bibek; Knoesche, Thomas R.; Anwander, Alfred [Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig (Germany); Stepan, Holger [University Leipzig, Department of Obstetrics, Leipzig (Germany)

    2014-10-15

    Diffusion-weighted imaging (DWI) is important in the assessment of fetal brain development. However, it is clinically challenging and time-consuming to prepare neuromorphological examinations to assess real brain age and to detect abnormalities. To demonstrate that the Gini coefficient can be a simple, intuitive parameter for modelling fetal brain development. Postmortem fetal specimens(n = 28) were evaluated by diffusion-weighted imaging (DWI) on a 3-T MRI scanner using 60 directions, 0.7-mm isotropic voxels and b-values of 0, 150, 1,600 s/mm{sup 2}. Constrained spherical deconvolution (CSD) was used as the local diffusion model. Fractional anisotropy (FA), apparent diffusion coefficient (ADC) and complexity (CX) maps were generated. CX was defined as a novel diffusion metric. On the basis of those three parameters, the Gini coefficient was calculated. Study of fetal brain development in postmortem specimens was feasible using DWI. The Gini coefficient could be calculated for the combination of the three diffusion parameters. This multidimensional Gini coefficient correlated well with age (Adjusted R{sup 2} = 0.59) between the ages of 17 and 26 gestational weeks. We propose a new method that uses an economics concept, the Gini coefficient, to describe the whole brain with one simple and intuitive measure, which can be used to assess the brain's developmental state. (orig.)

  16. Functional Magnetic Resonance Study of Non-conventional Morphological Brains: malnourished rats

    Directory of Open Access Journals (Sweden)

    Martin R.

    2015-08-01

    Full Text Available Malnutrition during brain development can cause serious problems that can be irreversible. Dysfunctional patterns of brain activity can be detected with functional MRI. We used BOLD functional Magnetic Resonance Imaging (fMRI to investigate region differences of brain activity between control and malnourished rats. The food-competition method was applied to a rat model to induce malnutrition during lactation. A 7T magnet was used to detect changes of the BOLD signal associated with changes in brain activity caused by the trigeminal nerve stimulation in malnourished and control rats. Major neuronal activation was observed in malnourished rats in several brain regions, including cerebellum, somatosensory cortex, hippocampus, and hypothalamus. Statistical analysis of the BOLD signals from various brain areas revealed significant differences in somatosensory cortex between the control and experimental groups, as well as a significant difference between the cerebellum and other structures in the experimental group. This study, particularly in malnourished rats, demonstrates increased BOLD activation in the cerebellum.

  17. Bisquaternary oximes as reactivators of tabun-inhibited human brain cholinesterases: an in vitro study.

    Science.gov (United States)

    Kuca, Kamil; Jun, Daniel; Cabal, Jiri; Musilova, Lucie

    2007-07-01

    Intoxications caused by tabun nerve agent are generally very hard to treat by convential acetylcholinesterase (AChE) reactivators. Due to this, new AChE reactivators are still developed. In this study, we have tested three new promising bisquaternary AChE reactivators: K027, K033 and K048. These reactivators were previously tested on rat brain homogenate. To mimic reality, we studied the potency of these new oximes to reactivate tabun-inhibited human brain cholinesterases. As is evident from the results, reactivator K048 (reactivation 40%) surpassed all reactivators tested in this study [including the most promising ones, namely trimedoxime (37%) and obidoxime (33%)]. Moreover, if compared to our previous results from rat brain studies, species differences were demonstrated.

  18. Brain connectivity study of joint attention using frequency-domain optical imaging technique

    Science.gov (United States)

    Chaudhary, Ujwal; Zhu, Banghe; Godavarty, Anuradha

    2010-02-01

    Autism is a socio-communication brain development disorder. It is marked by degeneration in the ability to respond to joint attention skill task, from as early as 12 to 18 months of age. This trait is used to distinguish autistic from nonautistic populations. In this study, diffuse optical imaging is being used to study brain connectivity for the first time in response to joint attention experience in normal adults. The prefrontal region of the brain was non-invasively imaged using a frequency-domain based optical imager. The imaging studies were performed on 11 normal right-handed adults and optical measurements were acquired in response to joint-attention based video clips. While the intensity-based optical data provides information about the hemodynamic response of the underlying neural process, the time-dependent phase-based optical data has the potential to explicate the directional information on the activation of the brain. Thus brain connectivity studies are performed by computing covariance/correlations between spatial units using this frequency-domain based optical measurements. The preliminary results indicate that the extent of synchrony and directional variation in the pattern of activation varies in the left and right frontal cortex. The results have significant implication for research in neural pathways associated with autism that can be mapped using diffuse optical imaging tools in the future.

  19. The use of magnetic resonance imaging to study the brain size of young children with autism

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    Farah Ashrafzadeh

    2016-07-01

    Full Text Available Introduction: Autism spectrum disorder (ASD is a syndrome of social communication deficits and repetitive behaviors or restricted interests. While the impairments associated with ASD tend to deteriorate from childhood into adulthood, it is of critical importance that the syndrome is diagnosed at an early age. One means of facilitating this is through understanding how the brain of people with ASD develops from early childhood. Magnetic resonance imaging (MRI is the method of choice for in vivo and non-invasive investigations of the morphology of the human brain, especially when the subjects are children. In this study, we conducted a systematic review of existing structural MRI studies that have investigated brain size in ASD children of up to 5 years old. Methods: In this study, we systematically reviewed published papers that describe research studies in which the brain size of ASD children has been examined. PubMed and Scopus databases were searched for all relevant original articles that described the use of MRI techniques to study ASD patients who were between 1 and 5 years old. To be included in the review, all studies needed to be cohort and case series that involved at least 10 patients. No time limitations were placed on the searched articles within the inclusion criteria. The exclusion criteria were non-English articles, case reports, and articles that described research involving subjects that were not within the qualifying age range of 1-5 years old.Result: After an initial screening process through which the title, abstracts, and full text of the articles were reviewed to confirm they met the inclusion criteria, a total of 10 relevant articles were studied in depth. All studies found that children with ASD who were within the selected age range had a larger brain size than children without ASD.Discussion: The findings of recent studies indicate that the vast majority of ASD patients exhibit an enlarged brain; however, the extent of

  20. Aerobic Exercise Intervention, Cognitive Performance, and Brain Structure: Results from the Physical Influences on Brain in Aging (PHIBRA) Study.

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    Jonasson, Lars S; Nyberg, Lars; Kramer, Arthur F; Lundquist, Anders; Riklund, Katrine; Boraxbekk, Carl-Johan

    2016-01-01

    Studies have shown that aerobic exercise has the potential to improve cognition and reduce brain atrophy in older adults. However, the literature is equivocal with regards to the specificity or generality of these effects. To this end, we report results on cognitive function and brain structure from a 6-month training intervention with 60 sedentary adults (64-78 years) randomized to either aerobic training or stretching and toning control training. Cognitive functions were assessed with a neuropsychological test battery in which cognitive constructs were measured using several different tests. Freesurfer was used to estimate cortical thickness in frontal regions and hippocampus volume. Results showed that aerobic exercisers, compared to controls, exhibited a broad, rather than specific, improvement in cognition as indexed by a higher "Cognitive score," a composite including episodic memory, processing speed, updating, and executive function tasks (p = 0.01). There were no group differences in cortical thickness, but additional analyses revealed that aerobic fitness at baseline was specifically related to larger thickness in dorsolateral prefrontal cortex (dlPFC), and hippocampus volume was positively associated with increased aerobic fitness over time. Moreover, "Cognitive score" was related to dlPFC thickness at baseline, but changes in "Cognitive score" and dlPFC thickness were associated over time in the aerobic group only. However, aerobic fitness did not predict dlPFC change, despite the improvement in "Cognitive score" in aerobic exercisers. Our interpretation of these observations is that potential exercise-induced changes in thickness are slow, and may be undetectable within 6-months, in contrast to change in hippocampus volume which in fact was predicted by the change in aerobic fitness. To conclude, our results add to a growing literature suggesting that aerobic exercise has a broad influence on cognitive functioning, which may aid in explaining why

  1. Allometric scaling of brain regions to intra-cranial volume: An epidemiological MRI study.

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    de Jong, Laura W; Vidal, Jean-Sébastien; Forsberg, Lars E; Zijdenbos, Alex P; Haight, Thaddeus; Sigurdsson, Sigurdur; Gudnason, Vilmundur; van Buchem, Mark A; Launer, Lenore J

    2017-01-01

    There is growing evidence that sub-structures of the brain scale allometrically to total brain size, that is, in a non-proportional and non-linear way. Here, scaling of different volumes of interest (VOI) to intra-cranial volume (ICV) was examined. It was assessed whether scaling was allometric or isometric and whether scaling coefficients significantly differed from each other. We also tested to what extent allometric scaling of VOI was introduced by the automated segmentation technique. Furthermore, reproducibility of allometric scaling was studied different age groups and study populations. Study samples included samples of cognitively healthy adults from the community-based Age Gene/Environment Susceptibility-Reykjavik Study (AGES-Reykjavik Study) (N = 3,883), the Coronary Artery Risk Development in Young Adults Study (CARDIA) (N =709), and the Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 180). Data encompassed participants with different age, ethnicity, risk factor profile, and ICV and VOI obtained with different automated MRI segmentation techniques. Our analysis showed that (1) allometric scaling is a trait of all parts of the brain, (2) scaling of neo-cortical white matter, neo-cortical gray matter, and deep gray matter structures including the cerebellum are significantly different from each other, and (3) allometric scaling of brain structures cannot solely be explained by age-associated atrophy, sex, ethnicity, or a systematic bias from study-specific segmentation algorithm, but appears to be a true feature of brain geometry. Hum Brain Mapp 38:151-164, 2017. © 2016 Wiley Periodicals, Inc.

  2. Food and drug cues activate similar brain regions: a meta-analysis of functional MRI studies.

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    Tang, D W; Fellows, L K; Small, D M; Dagher, A

    2012-06-06

    In healthy individuals, food cues can trigger hunger and feeding behavior. Likewise, smoking cues can trigger craving and relapse in smokers. Brain imaging studies report that structures involved in appetitive behaviors and reward, notably the insula, striatum, amygdala and orbital frontal cortex, tend to be activated by both visual food and smoking cues. Here, by carrying out a meta-analysis of human neuro-imaging studies, we investigate the neural network activated by: 1) food versus neutral cues (14 studies, 142 foci) 2) smoking versus neutral cues (15 studies, 176 foci) 3) smoking versus neutral cues when correlated with craving scores (7 studies, 108 foci). PubMed was used to identify cue-reactivity imaging studies that compared brain response to visual food or smoking cues to neutral cues. Fourteen articles were identified for the food meta-analysis and fifteen articles were identified for the smoking meta-analysis. Six articles were identified for the smoking cue correlated with craving analysis. Meta-analyses were carried out using activation likelihood estimation. Food cues were associated with increased blood oxygen level dependent (BOLD) response in the left amygdala, bilateral insula, bilateral orbital frontal cortex, and striatum. Smoking cues were associated with increased BOLD signal in the same areas, with the exception of the insula. However, the smoking meta-analysis of brain maps correlating cue-reactivity with subjective craving did identify the insula, suggesting that insula activation is only found when craving levels are high. The brain areas identified here are involved in learning, memory and motivation, and their cue-induced activity is an index of the incentive salience of the cues. Using meta-analytic techniques to combine a series of studies, we found that food and smoking cues activate comparable brain networks. There is significant overlap in brain regions responding to conditioned cues associated with natural and drug rewards.

  3. A Phase I Study of Short-Course Accelerated Whole Brain Radiation Therapy for Multiple Brain Metastases

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    Caravatta, Luciana; Deodato, Francesco; Ferro, Marica [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Massaccesi, Mariangela [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Cilla, Savino [Medical Physics Unit, Fondazione di Ricerca e Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Padula, Gilbert D.A. [Department of Radiation Oncology, The Lacks Cancer Center Saint Mary' s Health Care, Grand Rapids, Michigan (United States); Mignogna, Samantha; Tambaro, Rosa [Department of Palliative Therapies, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Carrozza, Francesco [Department of Oncology, A. Cardarelli Hospital, Campobasso (Italy); Flocco, Mariano [Madre Teresa di Calcutta Hospice, Larino (Italy); Cantore, Giampaolo [Department of Neurological Sciences, Istituto Neurologico Mediterraneo Neuromed, Istituto di Ricovero e Cura a Carattere Scientifico, Pozzilli (Italy); Scapati, Andrea [Department of Radiation Oncology, ' San Francesco' Hospital, Nuoro (Italy); Buwenge, Milly [Department of Radiotherapy, Mulago Hospital, Kampala (Uganda); and others

    2012-11-15

    Purpose: To define the maximum tolerated dose (MTD) of a SHort-course Accelerated whole brain RadiatiON therapy (SHARON) in the treatment of patients with multiple brain metastases. Methods and Materials: A phase 1 trial in 4 dose-escalation steps was designed: 12 Gy (3 Gy per fraction), 14 Gy (3.5 Gy per fraction), 16 Gy (4 Gy per fraction), and 18 Gy (4.5 Gy per fraction). Eligibility criteria included patients with unfavorable recursive partitioning analysis (RPA) class > or =2 with at least 3 brain metastases or metastatic disease in more than 3 organ systems, and Eastern Cooperative Oncology Group (ECOG) performance status {<=}3. Treatment was delivered in 2 days with twice-daily fractionation. Patients were treated in cohorts of 6-12 to define the MTD. The dose-limiting toxicity (DLT) was defined as any acute toxicity {>=}grade 3, according to the Radiation Therapy Oncology Group scale. Information on the status of the main neurologic symptoms and quality of life were recorded. Results: Characteristics of the 49 enrolled patients were as follows: male/female, 30/19; median age, 66 years (range, 23-83 years). ECOG performance status was <3 in 46 patients (94%). Fourteen patients (29%) were considered to be in recursive partitioning analysis (RPA) class 3. Grade 1-2 acute neurologic (26.4%) and skin (18.3%) toxicities were recorded. Only 1 patient experienced DLT (neurologic grade 3 acute toxicity). With a median follow-up time of 5 months (range, 1-23 months), no late toxicities have been observed. Three weeks after treatment, 16 of 21 symptomatic patients showed an improvement or resolution of presenting symptoms (overall symptom response rate, 76.2%; confidence interval 0.95: 60.3-95.9%). Conclusions: Short-course accelerated radiation therapy in twice-daily fractions for 2 consecutive days is tolerated up to a total dose of 18 Gy. A phase 2 study has been planned to evaluate the efficacy on overall survival, symptom control, and quality of life indices.

  4. A PROSPECTIVE HISTOPATHOLOGICAL-BASED STUDY OF BRAIN TUMOURS IN A REFERRAL CENTRE

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    Prathima Gujjaru

    2016-07-01

    Full Text Available BACKGROUND Brain neoplasms occur at all ages and account for around 2-3 percent of all deaths in adults. In children, the frequency increases to more than twenty percent. In children, it forms the second most common type of malignancy. Most of the tumours encountered are not related to any identifiable risk factors except for irradiation and some hereditary syndromes like subependymal giant cell astrocytoma, glioblastoma multiforme, cerebellar haemangioblastoma, meningioma, Schwannoma of 7 th cranial nerve. Gliomas constitute fifty percent of the brain tumours and sixty percent of all gliomas are glioblastoma multiforme. Meningiomas constitute twenty percent and cerebral metastasis is seen in fifteen percent of the cases. Seventy percent of supratentorial tumours are found in adults and seventy percent of brain tumours in children are infratentorial. The three common tumours of cerebellum are medulloblastoma, haemangioblastoma and juvenile pilocytic astrocytoma. Brain tumours are space occupying lesions and cause compression and destruction of adjacent structures, brain oedema (Peritumoural tissue, infarction and ischaemia of brain by compressing/infiltrating cerebral blood vessels, obstruction of CSF flow causing hydrocephalus, and rise in intracranial pressure with herniations. Tumours can undergo ischaemic necrosis and necrotic tumours tend to bleed. Brain tumours generally do not metastasise. Schwannoma and meningioma are benign tumours. Medulloblastoma of childhood may have drop metastasis via CSF. A sincere effort has been put in this study to identify the incidence of each variety of brain tumour among the fifty confirmed and identified cases of brain tumours. METHODS The age range of the cases in present study was 5-72 years with a mean age of occurrence of 44.11 years and the peak age group affected were in the 3 rd and 4 th decades. Cerebral hemisphere was the commonest site for intracranial tumours. RESULT In the present study, fifty

  5. [The amygdaloid body of the brain: some topics for discussion and little-studied problems].

    Science.gov (United States)

    Akmaev, I G; Kalimullina, L B

    1995-01-01

    Features of functional morphology of the amygdaloid brain complex (ABC) are analyzed in a new light presenting the notion of the ABC as a nucleo-paleocortical structure. The analysis of the structural organization of ABC could imply the presence of phylogenetically differentiated parts: the ancient, the old and the new amygdala. The presentation carries original data on the morphometric and histophysiological studies under various experimental alterations of the endocrine system. A concept is developed of the existence of a rostrocaudal gradient in the expression of sex-dependent structural and functional features of the amygdaloid complex as a neuroendocrine brain centre. Provided is technical recommendation for use in biological studies of amygdaloid brain complex mathematical models based on the theory of image identification. An original technique has also been recommended for selective dissection of the ABC with its eventual removal from nonfixed brain, which allows studies to be made of the ABC neurophysiological and neurochemical properties on surviving slices. Evidence is adduced indicating involvement of the ABC in the process of the brain sex differentiation.

  6. Brain imaging and human nutrition: which measures to use in intervention studies?

    Science.gov (United States)

    Sizonenko, Stéphane V; Babiloni, Claudio; de Bruin, Eveline A; Isaacs, Elizabeth B; Jönsson, Lena S; Kennedy, David O; Latulippe, Marie E; Mohajeri, M Hasan; Moreines, Judith; Pietrini, Pietro; Walhovd, Kristine B; Winwood, Robert J; Sijben, John W

    2013-08-01

    The present review describes brain imaging technologies that can be used to assess the effects of nutritional interventions in human subjects. Specifically, we summarise the biological relevance of their outcome measures, practical use and feasibility, and recommended use in short- and long-term nutritional studies. The brain imaging technologies described consist of MRI, including diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI, as well as electroencephalography/magnetoencephalography, near-IR spectroscopy, positron emission tomography and single-photon emission computerised tomography. In nutritional interventions and across the lifespan, brain imaging can detect macro- and microstructural, functional, electrophysiological and metabolic changes linked to broader functional outcomes, such as cognition. Imaging markers can be considered as specific for one or several brain processes and as surrogate instrumental endpoints that may provide sensitive measures of short- and long-term effects. For the majority of imaging measures, little information is available regarding their correlation with functional endpoints in healthy subjects; therefore, imaging markers generally cannot replace clinical endpoints that reflect the overall capacity of the brain to behaviourally respond to specific situations and stimuli. The principal added value of brain imaging measures for human nutritional intervention studies is their ability to provide unique in vivo information on the working mechanism of an intervention in hypothesis-driven research. Selection of brain imaging techniques and target markers within a given technique should mainly depend on the hypothesis regarding the mechanism of action of the intervention, level (structural, metabolic or functional) and anticipated timescale of the intervention's effects, target population, availability and costs of the techniques.

  7. Prolonged repeated acupuncture stimulation induces habituation effects in pain-related brain areas: an FMRI study.

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    Chuanfu Li

    Full Text Available Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36. Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia.

  8. Brain deactivation in the outperformance in bimodal tasks: an FMRI study