scholarly journals Polymorphic glutathione S-transferase subunit 3 of rat liver exhibits different susceptibilities to carbon tetrachloride: differences in their interactions with heat-shock protein 90

2003 ◽  
Vol 372 (2) ◽  
pp. 611-616 ◽  
Author(s):  
Jun MAYAMA ◽  
Takayuki KUMANO ◽  
Makoto HAYAKARI ◽  
Takehiko YAMAZAKI ◽  
Shu AIZAWA ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Glutathione S Transferase ◽  
Ccl4 Administration ◽  
A Subunit ◽  
Rat Livers

Rat glutathione S-transferase (GST) subunit 3 gene has polymorphism, one type encoding Asn198-Cys199 (NC type) and another encoding Lys198-Ser199 (KS type). To examine whether the two types of GST 3-3 exhibit different susceptibilities to oxidative stress in vivo, rats were administered with CCl4, a hepatotoxin causing severe oxidative stress, and its effect on liver GST 3-3 was compared. Decrease in GST activities in liver due to CCl4 administration was more evident in NC type rats than in KS type rats, and most GST activities of KS type rats were confined to S-hexylglutathione–Sepharose, whereas those of NC type rats were not. Decreases in GST subunits 1 and 3 were more marked in NC type rats and glutathiolated NC type GST 3-3 was also detected. These results indicated that KS and NC type GST 3-3 of rat livers exhibited different susceptibilities to CCl4in vivo. A protein consisting of a subunit with molecular mass of 90 kDa was shown to bind to KS type GST 3-3 but not to NC type. This protein was identified as heat-shock protein (HSP) 90β by N-terminal amino acid sequencing and immunoblotting. A specific HSP90 inhibitor geldanamycin released their binding. There was no difference in the binding of apoptosis signal-regulating kinase 1 to GST 3-3 between NC and KS type rats. These findings suggest that HSP90 interacts with KS type GST 3-3 and thereby protects it from inactivation due to CCl4.

Heat shock protein 90-binding agents protect renal cells from oxidative stress and reduce kidney ischemia-reperfusion injury

2008 ◽  
Vol 295 (2) ◽  
pp. F397-F405 ◽  
Author(s):  
Ewen M. Harrison ◽  
Eva Sharpe ◽  
Christopher O. Bellamy ◽  
Stephen J. McNally ◽  
Luke Devey ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Heat Shock Protein 90 ◽  
Renal Protection ◽  
Kidney Ischemia

Heat shock proteins (Hsps) are protective in models of transplantation, yet practical strategies to upregulate them remain elusive. The heat shock protein 90-binding agent (HBA) geldanamycin and its analogs (17-AAG and 17-DMAG) are known to upregulate Hsps and confer cellular protection but have not been investigated in a model relevant to transplantation. We examined the ability of HBAs to upregulate Hsp expression and confer protection in renal adenocarcinoma (ACHN) cells in vitro and in a mouse model of kidney ischemia-reperfusion (I/R) injury. Hsp70 gene expression was increased 30-40 times in ACHN cells treated with HBAs, and trimerization and DNA binding of heat shock transcription factor-1 (HSF1) were demonstrated. A three- and twofold increase in Hsp70 and Hsp27 protein expression, respectively, was found in ACHN cells treated with HBAs. HBAs protected ACHN cells from an H2O2-mediated oxidative stress, and HSF1 short interfering RNA was found to abrogate HBA-mediated Hsp induction and protection. In vivo, Hsp70 was upregulated in the kidneys, liver, lungs, and heart of HBA-treated mice. This was associated with a functional and morphological renal protection from I/R injury. Therefore, HBAs mediate upregulation of protective Hsps in mouse kidneys which are associated with reduced I/R injury and may be useful in reducing transplant-associated kidney injury.

scholarly journals Synergism of Heat Shock Protein 90 and Histone Deacetylase Inhibitors in Synovial Sarcoma

Sarcoma ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Anne Nguyen ◽  
Le Su ◽  
Belinda Campbell ◽  
Neal M. Poulin ◽  
Torsten O. Nielsen
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Synovial Sarcoma ◽  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Hdac Inhibitors ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Therapeutic Benefit ◽  
Multiple Time

Current systemic therapies have little curative benefit for synovial sarcoma. Histone deacetylase (HDAC) inhibitors and the heat shock protein 90 (Hsp90) inhibitor 17-AAG have recently been shown to inhibit synovial sarcoma in preclinical models. We tested combinations of 17-AAG with the HDAC inhibitor MS-275 for synergism by proliferation and apoptosis assays. The combination was found to be synergistic at multiple time points in two synovial sarcoma cell lines. Previous studies have shown that HDAC inhibitors not only induce cell death but also activate the survival pathway NF-κB, potentially limiting therapeutic benefit. As 17-AAG inhibits activators of NF-κB, we tested if 17-AAG synergizes with MS-275 through abrogating NF-κB activation. In our assays, adding 17-AAG blocks NF-κB activation by MS-275 and siRNA directed against histone deacetylase 3 (HDAC3) recapitulates the effects of MS-275. Additionally, we find that the NF-κB inhibitor BAY 11-7085 synergizes with MS-275. We conclude that agents inhibiting NF-κB synergize with HDAC inhibitors against synovial sarcoma.

Heat shock protein 90 inhibitors attenuate LPS-induced endothelial hyperpermeability

2008 ◽  
Vol 294 (4) ◽  
pp. L755-L763 ◽  
Author(s):  
Anuran Chatterjee ◽  
Connie Snead ◽  
Gunay Yetik-Anacak ◽  
Galina Antonova ◽  
Jingmin Zeng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heat Shock ◽  
Lung Injury ◽  
Heat Shock Protein ◽  
Adherens Junction ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Barrier Dysfunction ◽  
Focal Adhesion Protein ◽  
Endothelial Hyperpermeability

Endothelial hyperperme ability leading to vascular leak is an important consequence of sepsis and sepsis-induced lung injury. We previously reported that heat shock protein (hsp) 90 inhibitor pretreatment improved pulmonary barrier dysfunction in a murine model of sepsis-induced lung injury. We now examine the effects of hsp90 inhibitors on LPS-mediated endothelial hyperpermeability, as reflected in changes in transendothelial electrical resistance (TER) of bovine pulmonary arterial endothelial cells (BPAEC). Vehicle-pretreated cells exposed to endotoxin exhibited a concentration-dependent decrease in TER, activation of pp60Src, phosphorylation of the focal adhesion protein paxillin, and reduced expression of the adherens junction proteins, vascular endothelial (VE)-cadherin and β-catenin. Pretreatment with the hsp90 inhibitor, radicicol, prevented the decrease in TER, maintained VE-cadherin and β-catenin expression, and inhibited activation of pp60Src and phosphorylation of paxillin. Similarly, when BPAEC hyperpermeability was induced by endotoxin-activated neutrophils, pretreatment of neutrophils and/or endothelial cells with radicicol protected against the activated neutrophil-induced decrease in TER. Increased paxillin phosphorylation and decreased expression of β-catenin and VE-cadherin were also observed in mouse lungs 12 h after intraperitoneal endotoxin and attenuated in mice pretreated with radicicol. These results suggest that hsp90 plays an important role in sepsis-associated endothelial barrier dysfunction.

scholarly journals RNA-binding proteins and heat-shock protein 90 are constituents of the cytoplasmic capping enzyme interactome

2018 ◽  
Vol 293 (43) ◽  
pp. 16596-16607 ◽  
Author(s):  
Jackson B. Trotman ◽  
Bernice A. Agana ◽  
Andrew J. Giltmier ◽  
Vicki H. Wysocki ◽  
Daniel R. Schoenberg
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mammalian Cells ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Capping Enzyme ◽  
Eukaryotic Mrnas

The N7-methylguanosine cap is added in the nucleus early in gene transcription and is a defining feature of eukaryotic mRNAs. Mammalian cells also possess cytoplasmic machinery for restoring the cap at uncapped or partially degraded RNA 5′ ends. Central to both pathways is capping enzyme (CE) (RNA guanylyltransferase and 5′-phosphatase (RNGTT)), a bifunctional, nuclear and cytoplasmic enzyme. CE is recruited to the cytoplasmic capping complex by binding of a C-terminal proline-rich sequence to the third Src homology 3 (SH3) domain of NCK adapter protein 1 (NCK1). To gain broader insight into the cellular context of cytoplasmic recapping, here we identified the protein interactome of cytoplasmic CE in human U2OS cells through two complementary approaches: chemical cross-linking and recovery with cytoplasmic CE and protein screening with proximity-dependent biotin identification (BioID). This strategy unexpectedly identified 66 proteins, 52 of which are RNA-binding proteins. We found that CE interacts with several of these proteins independently of RNA, mediated by sequences within its N-terminal triphosphatase domain, and we present a model describing how CE-binding proteins may function in defining recapping targets. This analysis also revealed that CE is a client protein of heat shock protein 90 (HSP90). Nuclear and cytoplasmic CEs were exquisitely sensitive to inhibition of HSP90, with both forms declining significantly following treatment with each of several HSP90 inhibitors. Importantly, steady-state levels of capped mRNAs decreased in cells treated with the HSP90 inhibitor geldanamycin, raising the possibility that the cytotoxic effect of these drugs may partially be due to a general reduction in translatable mRNAs.

scholarly journals Inhibition of heat shock protein 90 prolongs survival of mice with BCR-ABL-T315I–induced leukemia and suppresses leukemic stem cells

Blood ◽  
2007 ◽  
Vol 110 (2) ◽  
pp. 678-685 ◽  
Author(s):  
Cong Peng ◽  
Julia Brain ◽  
Yiguo Hu ◽  
Ami Goodrich ◽  
Linghong Kong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Myelogenous Leukemia ◽  
Leukemia Stem Cells

Abstract Development of kinase domain mutations is a major drug-resistance mechanism for tyrosine kinase inhibitors (TKIs) in cancer therapy. A particularly challenging example is found in Philadelphia chromosome–positive chronic myelogenous leukemia (CML) where all available kinase inhibitors in clinic are ineffective against the BCR-ABL mutant, T315I. As an alternative approach to kinase inhibition, an orally administered heat shock protein 90 (Hsp90) inhibitor, IPI-504, was evaluated in a murine model of CML. Treatment with IPI-504 resulted in BCR-ABL protein degradation, decreased numbers of leukemia stem cells, and prolonged survival of leukemic mice bearing the T315I mutation. Hsp90 inhibition more potently suppressed T315I-expressing leukemia clones relative to the wild-type (WT) clones in mice. Combination treatment with IPI-504 and imatinib was more effective than either treatment alone in prolonging survival of mice simultaneously bearing both WT and T315I leukemic cells. These results provide a rationale for use of an Hsp90 inhibitor as a first-line treatment in CML by inhibiting leukemia stem cells and preventing the emergence of imatinib-resistant clones in patients. Rather than inhibiting kinase activity, elimination of mutant kinases provides a new therapeutic strategy for treating BCR-ABL–induced leukemia as well as other cancers resistant to treatment with tyrosine kinase inhibitors.

scholarly journals A Brain Penetrating Heat-Shock Protein 90 Inhibitor NXD30001 Inhibits Glioblastoma as a Monotherapy or in Combination With Radiation

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Hao Chen ◽  
Jialiang Wang ◽  
Hengli Tian
Keyword(s):  
Stem Cells ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Median Survival ◽  
Therapeutic Potential ◽  
Heat Shock Protein 90 ◽  
Tumor Bearing ◽  
Client Proteins

Abstract INTRODUCTION It has been increasingly recognized that glioblastoma multiforme (GBM) is a highly heterogeneous disease, which is initiated and sustained by molecular alterations in an array of signal transduction pathways. Heat-shock protein 90 (Hsp90) is a molecular chaperone to be critically implicated in folding and activation of a diverse group of client proteins, many of which are key regulators of important glioblastoma biology. METHODS To determine the therapeutic potential of targeting Hsp90 in glioblastoma, we assessed the anti-neoplastic efficacy of NXD30001, a brain-penetrating Hsp90 inhibitor as a monotherapy or in combination with radiation, both in Vitro and in Vivo. RESULTS Our results demonstrated that NXD30001 potently inhibited neurosphere formation, growth and survival of CD133 + glioblastoma stem cells (GSCs) with the half maximal inhibitory concentrations (IC50) at low nanomolar concentrations. At suboptimal concentrations, inhibition of Hsp90 did not exert cytotoxic activity but rather increased radiosensitivity in GSCs. CD133- GBM cells were less sensitive and not radiosensitized by NXD30001. In lines with its cytotoxic and radiosensitizing effects, NXD30001 dose-dependently decreased phosphorylation protein levels of multiple Hsp90 client proteins, including those playing key roles in GSCs, such as EGFR, Akt, c-Myc, and Notch1. In addition, combining NXD30001 with radiation could impair DNA damage response and ER stress response to induce apoptosis of GSCs. Treatment of orthotopic glioblastoma tumors with NXD30001 extended median survival of tumor-bearing mice by approximately 20% (treated 37 days vs vehicle 31 d, P = .0026). Radiation alone increased median survival of tumor-bearing mice from 31 to 38 d, combination with NXD30001 further extended survival to 43 d (P = .0089). CONCLUSION Our results suggest that GBM stem cells (CD133+) are more sensitive to NXD30001 than non-stem GBM cells (CD133-). Furthermore, combination NXD30001 with radiation significantly inhibits GBM progression than use it as a monotherapy by targeting GSCs.

Sign in / Sign up

Export Citation Format

Share Document