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Kim JW, Cho YB, Lee S. Cell Surface GRP94 as a Novel Emerging Therapeutic Target for Monoclonal Antibody Cancer Therapy. Cells 2021; 10:cells10030670. [PMID: 33802964 PMCID: PMC8002708 DOI: 10.3390/cells10030670] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/11/2021] [Accepted: 03/14/2021] [Indexed: 12/15/2022] Open
Abstract
Glucose-regulated protein 94 (GRP94) is an endoplasmic reticulum (ER)-resident member of the heat shock protein 90 (HSP90) family. In physiological conditions, it plays a vital role in regulating biological functions, including chaperoning cellular proteins in the ER lumen, maintaining calcium homeostasis, and modulating immune system function. Recently, several reports have shown the functional role and clinical relevance of GRP94 overexpression in the progression and metastasis of several cancers. Therefore, the current review highlights GRP94’s physiological and pathophysiological roles in normal and cancer cells. Additionally, the unmet medical needs of small chemical inhibitors and the current development status of monoclonal antibodies specifically targeting GRP94 will be discussed to emphasize the importance of cell surface GRP94 as an emerging therapeutic target in monoclonal antibody therapy for cancer.
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Oliveira CAF, Ivanova L, Solhaug A, Fæste CK. Enniatin B 1-induced lysosomal membrane permeabilization in mouse embryonic fibroblasts. Mycotoxin Res 2019; 36:23-30. [PMID: 31264166 DOI: 10.1007/s12550-019-00366-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/07/2019] [Accepted: 06/17/2019] [Indexed: 11/25/2022]
Abstract
The mycotoxin enniatin B1 (ENN B1) is widely present in grain-based feed and food products. In the present study, we have investigated how this lipophilic and ionophoric molecule can affect the lysosomal stability and chaperone-mediated autophagy (CMA) in wild-type (WT) and in lysosome-associated membrane proteins (LAMP)-1/2 double-deficient (DD) mouse embryonic fibroblasts (MEF). The cell viability and lysosomal pH were assessed using the Neutral Red (NR) cytotoxicity assay and the LysoSensor® Yellow/Blue DND-160, respectively. Changes in the expression of the CMA-related components LAMP-2 and the chaperones heat shock cognate (hsc) 70 and heat shock protein (hsp) 90 were determined in cytosolic extracts by immunoblotting. In the NR assay, LAMP-1/2 DD MEF cells were significantly less sensitive to ENN B1 than WT MEF cells after 24 h exposure to ENN B1 at levels of 2.5-10 μmol/L. Exposure to ENN B1 at concentrations below the half maximal effective concentration (EC50) (1.5-1.7 μmol/L) increased the lysosomal pH in WT MEF, but not in LAMP-1/2 DD cells, suggesting that lysosomal LAMP-2 is an early target of ENN B1-induced lysosomal alkalization and cytotoxicity in MEF cells. Additionally, cytosolic hsp90 and LAMP-2 levels slightly increased after exposure for 4 h, indicating lysosomal membrane permeabilization (LMP). In summary, it appeared that ENN B1 can destabilize the LAMP-2 complex in the lysosomal membrane at concentrations close to the EC50, resulting in the alkalinization of lysosomes, partial LMP, and thereby leakage of CMA-associated components into the cytosol.
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Affiliation(s)
- Carlos A F Oliveira
- Department of Food Engineering, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, SP, 13635-900, Brazil.
| | - Lada Ivanova
- Chemistry Section, Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106, Oslo, Norway
| | - Anita Solhaug
- Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106, Oslo, Norway
| | - Christiane K Fæste
- Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106, Oslo, Norway
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Martins E, Silva V, Lemos A, Palmeira A, Puthongking P, Sousa E, Rocha-Pereira C, Ghanem CI, Carmo H, Remião F, Silva R. Newly Synthesized Oxygenated Xanthones as Potential P-Glycoprotein Activators: In Vitro, Ex Vivo, and In Silico Studies. Molecules 2019; 24:molecules24040707. [PMID: 30781374 PMCID: PMC6412186 DOI: 10.3390/molecules24040707] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/01/2019] [Accepted: 02/09/2019] [Indexed: 12/03/2022] Open
Abstract
P-glycoprotein (P-gp) plays a crucial role in the protection of susceptible organs, by significantly decreasing the absorption/distribution of harmful xenobiotics and, consequently, their toxicity. Therefore, P-gp has been proposed as a potential antidotal pathway, when activated and/or induced. Knowing that xanthones are known to interact with P-gp, the main goal was to study P-gp induction or/and activation by six new oxygenated xanthones (OX 1-6). Furthermore, the potential protection of Caco-2 cells against paraquat cytotoxicity was also assessed. The most promising compound was further tested for its ability to increase P-gp activity ex vivo, using everted intestinal sacs from adult Wistar-Han rats. The oxygenated xanthones interacted with P-gp in vitro, increasing P-gp expression and/or activity 24 h after exposure. Additionally, after a short-incubation period, several xanthones were identified as P-gp activators, as they immediately increased P-gp activity. Moreover, some xanthones decreased PQ cytotoxicity towards Caco-2 cells, an effect prevented under P-gp inhibition. Ex vivo, a significant increase in P-gp activity was observed in the presence of OX6, which was selectively blocked by a model P-gp inhibitor, zosuquidar, confirming the in vitro results. Docking simulations between a validated P-gp model and the tested xanthones predicted these interactions, and these compounds also fitted onto previously described P-gp induction and activation pharmacophores. In conclusion, the in vitro, ex vivo, and in silico results suggest the potential of some of the oxygenated xanthones in the modulation of P-gp, disclosing new perspectives in the therapeutics of intoxications by P-gp substrates.
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Affiliation(s)
- Eva Martins
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Vera Silva
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Agostinho Lemos
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Andreia Palmeira
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Ploenthip Puthongking
- Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
| | - Emília Sousa
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
| | - Carolina Rocha-Pereira
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Carolina I Ghanem
- Universidad de Buenos Aires, CONICET, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires C1053, Argentina.
| | - Helena Carmo
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Fernando Remião
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Renata Silva
- UCIBIO-REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
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Smiles WJ, Parr EB, Coffey VG, Lacham-Kaplan O, Hawley JA, Camera DM. Protein coingestion with alcohol following strenuous exercise attenuates alcohol-induced intramyocellular apoptosis and inhibition of autophagy. Am J Physiol Endocrinol Metab 2016; 311:E836-E849. [PMID: 27677502 DOI: 10.1152/ajpendo.00303.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/20/2016] [Indexed: 01/16/2023]
Abstract
Alcohol ingestion decreases postexercise rates of muscle protein synthesis, but the mechanism(s) (e.g., increased protein breakdown) underlying this observation is unknown. Autophagy is an intracellular "recycling" system required for homeostatic substrate and organelle turnover; its dysregulation may provoke apoptosis and lead to muscle atrophy. We investigated the acute effects of alcohol ingestion on autophagic cell signaling responses to a bout of concurrent (combined resistance- and endurance-based) exercise. In a randomized crossover design, eight physically active males completed three experimental trials of concurrent exercise with either postexercise ingestion of alcohol and carbohydrate (12 ± 2 standard drinks; ALC-CHO), energy-matched alcohol and protein (ALC-PRO), or protein (PRO) only. Muscle biopsies were taken at rest and 2 and 8 h postexercise. Select autophagy-related gene (Atg) proteins decreased compared with rest with ALC-CHO (P < 0.05) but not ALC-PRO. There were parallel increases (P < 0.05) in p62 and PINK1 commensurate with a reduction in BNIP3 content, indicating a diminished capacity for mitochondria-specific autophagy (mitophagy) when alcohol and carbohydrate were coingested. DNA fragmentation increased in both alcohol conditions (P < 0.05); however, nuclear AIF accumulation preceded this apoptotic response with ALC-CHO only (P < 0.05). In contrast, increases in the nuclear content of p53, TFEB, and PGC-1α in ALC-PRO were accompanied by markers of mitochondrial biogenesis at the transcriptional (Tfam, SCO2, and NRF-1) and translational (COX-IV, ATPAF1, and VDAC1) level (P < 0.05). We conclude that alcohol ingestion following exercise triggers apoptosis, whereas the anabolic properties of protein coingestion may stimulate mitochondrial biogenesis to protect cellular homeostasis.
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Affiliation(s)
- William J Smiles
- Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, Australia
| | - Evelyn B Parr
- Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, Australia
| | - Vernon G Coffey
- Bond Institute of Health and Sport and Faculty of Health Sciences and Medicine, Bond University, Robina, Queensland, Australia; and
| | - Orly Lacham-Kaplan
- Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, Australia
| | - John A Hawley
- Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, Australia
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Donny M Camera
- Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, Australia;
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Shin-Ya K. Novel Antitumor and Neuroprotective Substances Discovered by Characteristic Screenings Based on Specific Molecular Targets. Biosci Biotechnol Biochem 2014; 69:867-72. [PMID: 15914903 DOI: 10.1271/bbb.69.867] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the course of characteristic screening for antitumor substances, we isolated novel inhibitors against telomerase and the expression of molecular chaperone GRP78, designated telomestatin and versipelostatin, respectively. Telomestatin specifically acts on telomere sequence to stabilize the specific DNA structure called G-quadruplex and shows unique biological aspects that induce telomere dysfunction. Versipelostatin decreased the expression of GRP78 accompanied by a high level of cell death under glucose deprived conditions that mimicked the circumstances of a solid tumor. Furthermore, a screening program for glutamate receptor antagonist to treat brain stroke resulted in the isolation of an AMPA/NMDA antagonist kaitocephalin. Kaitocephalin potently protected rat hippocampal neurons from kainate, AMPA, and NMDA excitotoxicity. It also inhibited the Ca(2+) influx elicited by AMPA and NMDA, but not by kainate. Detailed analysis for the mode of action mechanism of these compounds indicated novel and unique biological phenomena not revealed by molecular biological techniques.
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Affiliation(s)
- Kazuo Shin-Ya
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan.
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Dash SK. Future targeted disease modifying drugs for Alzheimer's disease. Recent Pat CNS Drug Discov 2011; 6:65-76. [PMID: 21073430 DOI: 10.2174/157488911794079073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Accepted: 10/26/2010] [Indexed: 05/30/2023]
Abstract
Alzheimer's disease is the most common form of dementia. Alzheimer's disease will be responsible for an enormous burden on the individual and the society, as with the aging of the population, the incidence and the prevalence will grow. Presently, the drugs used in Alzheimer's disease are only effective symptomatically and improve functioning. They do not halt the progression of the disease. With the recent advances in our understanding of the pathogenesis of this disease, there have been tremendous advances in the clinical trials of compounds that can modify the disease process. Numerous therapeutic interventions and neuroprotective approaches are also in trial phase. It seems that in near future some of these compounds may be found effective and safe for use in this disease there by reducing the incidence of this disease in years to come, thereby lessen the burden due to it. In this article various compounds that can modify the course of the disease are discussed. Some recent patents and inventions for the treatment of Alzheimer's disease have also been discussed.
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Huang X, Zhang Z, Jia L, Zhao Y, Zhang X, Wu K. Endoplasmic reticulum stress contributes to vitamin E succinate-induced apoptosis in human gastric cancer SGC-7901 cells. Cancer Lett 2010; 296:123-31. [PMID: 20435408 DOI: 10.1016/j.canlet.2010.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 04/02/2010] [Accepted: 04/08/2010] [Indexed: 12/15/2022]
Abstract
Vitamin E succinate (RRR-alpha-tocopheryl succinate, VES), an efficient inducer of apoptosis, acts as a potent agent for cancer therapy. However, the mechanism by which VES mediates the effects are not yet fully understood. Here we studied the effect of endoplasmic reticulum (ER) stress and unfolded protein response (UPR) on VES-induced apoptosis of SGC-7901 human gastric cancer cells. VES caused cytological changes typical of apoptosis, increased ER dilation and cytosolic Ca(2+) concentration. And endogenous ER stress markers, GRP78 and GRP94 were transcriptionally and translationally altered. In response to VES, induction of CHOP, activation of caspase-4 and JNK were observed. Furthermore, VES also triggered activation of UPR components, including RNA-dependent protein kinase (PKR)-like ER kinase (PERK), activating transcription factor 6 (ATF6), X-box-binding protein 1 (XBP1), and ATF4 in a concentration- and time-dependent manner. Consequently, our results suggest that VES-induced apoptosis is coupled to ER stress and UPR activation in SGC-7901 human gastric cancer cells.
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Affiliation(s)
- Xiaoli Huang
- Department of Nutrition and Food, Harbin Medical University, Harbin, China
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8
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Pesce ER, Cockburn IL, Goble JL, Stephens LL, Blatch GL. Malaria heat shock proteins: drug targets that chaperone other drug targets. Infect Disord Drug Targets 2010; 10:147-157. [PMID: 20334623 DOI: 10.2174/187152610791163417] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 11/23/2009] [Indexed: 05/29/2023]
Abstract
Ongoing research into the chaperone systems of malaria parasites, and particularly of Plasmodium falciparum, suggests that heat shock proteins (Hsps) could potentially be an excellent class of drug targets. The P. falciparum genome encodes a vast range and large number of chaperones, including 43 Hsp40, six Hsp70, and three Hsp90 proteins (PfHsp40s, PfHsp70s and PfHsp90s), which are involved in a number of fundamental cellular processes including protein folding and assembly, protein translocation, signal transduction and the cellular stress response. Despite the fact that Hsps are relatively conserved across different species, PfHsps do exhibit a considerable number of unique structural and functional features. One PfHsp90 is thought to be sufficiently different to human Hsp90 to allow for selective targeting. PfHsp70s could potentially be used as drug targets in two ways: either by the specific inhibition of Hsp70s by small molecule modulators, as well as disruption of the interactions between Hsp70s and co-chaperones such as the Hsp70/Hsp90 organising protein (Hop) and Hsp40s. Of the many PfHsp40s present on the parasite, there are certain unique or essential members which are considered to have good potential as drug targets. This review critically evaluates the potential of Hsps as malaria drug targets, as well as the use of chaperones as aids in the heterologous expression of other potential malarial drug targets.
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Affiliation(s)
- E-R Pesce
- Biomedical Biotechnology Research Unit (BioBRU), Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa
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9
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Abstract
Background Hsp90 is an essential molecular chaperone that is also a novel anti-cancer drug target. There is growing interest in developing new drugs that modulate Hsp90 activity. Methodology/Principal Findings Using a virtual screening approach, 4-hydroxytamoxifen, the active metabolite of the anti-estrogen drug tamoxifen, was identified as a putative Hsp90 ligand. Surprisingly, while all drugs targeting Hsp90 inhibit the chaperone ATPase activity, it was found experimentally that 4-hydroxytamoxifen and tamoxifen enhance rather than inhibit Hsp90 ATPase. Conclusions/Significance Hence, tamoxifen and its metabolite are the first members of a new pharmacological class of Hsp90 activators.
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Affiliation(s)
- Rongmin Zhao
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Elisa Leung
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Stefan Grüner
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Matthieu Schapira
- Structural Genomics Consortium and Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (MS); (WAH)
| | - Walid A. Houry
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (MS); (WAH)
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Harashima K, Akimoto T, Nonaka T, Tsuzuki K, Mitsuhashi N, Nakano T. Heat shock protein 90 (Hsp90) chaperone complex inhibitor, Radicicol, potentiated radiation-induced cell killing in a hormone-sensitive prostate cancer cell line through degradation of the androgen receptor. Int J Radiat Biol 2009; 81:63-76. [PMID: 15962764 DOI: 10.1080/09553000400029460] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Until now, there has not been enough information on how androgens or androgen deprivation may influence the response of cancer cells to radiation. In this study, the effect of dihydrotestosterone (DHT) on cellular proliferative activity and radiosensitivity was examined in a hormone-sensitive human prostate cancer cell line, LNCaP. In addition, the study also examined how a heat shock protein 90 (Hsp90) chaperone complex inhibitor modified the effect of DHT on the radiosensitivity of the cells, because binding of the androgen receptor (AR) to Hsp90 is required to maintain the stability and functioning of AR. The hormone-sensitive human prostate cancer cell line, LNCaP, was used. Radicicol was used as one of the known Hsp90 chaperone complex inhibitors, and the cells were incubated in the presence of this compound at a concentration of 500 nM. Cellular radiosensitivity was determined by the clonogenic assay; the changes in the protein expression were examined by Western blotting or immunofluorescence. DHT at a concentration of 1 nM caused enhancement of the proliferative activity and reduction of the radiosensitivity of the cells. Radicicol at a concentration of 500 nM abolished the DHT-induced decrease in cellular radiosensitivity and potentiated the radiation-induced cell killing synergistically. Consistent with the changes in the cellular radiosensitivity, radicicol degraded AR, Raf-1 and HER2/neu via reduced binding of AR to Hsp90, although selective degradation of HER2/neu caused by Herceptin, a monoclonal antibody against HER2, did not affect the cellular radiosensitivity. The results suggest that the Hsp9O chaperone complex may be a potential molecular target for potentiation of radiation-induced cell killing in a hormone-sensitive prostate cancer cell line.
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Affiliation(s)
- K Harashima
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
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Umeda Y, Furihata K, Sakuda S, Nagasawa H, Ishigami K, Watanabe H, Izumikawa M, Takagi M, Doi T, Nakao Y, Shin-ya K. Absolute Structure of Prunustatin A, a Novel GRP78 Molecular Chaperone Down-Regulator. Org Lett 2007; 9:4239-42. [PMID: 17887691 DOI: 10.1021/ol7017856] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the course of our screening program for regulators of a molecular chaperone GRP78 expression, we isolated a novel inhibitor of GRP78 expression, designated as prunustatin A, from Streptomyces violaceoniger 4521-SVS3. The planar structure of prunustatin A was determined to be an oxidized type of the neoantimycin family. Its absolute stereochemistry was established to be 2R, 4S, 6S, 7R, 9S, and 29S by analyzing chemically degraded components obtained from the derivative of prunustatin A.
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Affiliation(s)
- Yukiko Umeda
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Abstract
A number of human diseases can be linked to aberrations in protein folding which cause an imbalance in protein homeostasis. Molecular chaperones, including heat shock proteins, act to assist protein folding, stability and activity in the cell. Attention has begun to focus on modulating the expression and/or activity of this group of proteins for the treatment of a wide variety of human diseases. This review will describe the progress made to date in developing pharmacological modulators of the heat shock response, including both agents which affect the entire heat shock response and those that specifically target the HSP70 and HSP90 chaperone families.
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Affiliation(s)
- Marissa V Powers
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton Surrey SM2 5NG, UK
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Puttaiah S, Biswas A, Staniszewska M, Nagaraj RH. Methylglyoxal inhibits glycation-mediated loss in chaperone function and synthesis of pentosidine in α-crystallin. Exp Eye Res 2007; 84:914-21. [PMID: 17368444 DOI: 10.1016/j.exer.2007.01.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 12/19/2006] [Accepted: 01/18/2007] [Indexed: 11/30/2022]
Abstract
Alpha-crystallin is a major protein in the eye lens and it functions as a molecular chaperone by preventing aggregation of mildly denatured proteins. Glycation, the reaction of sugars and ascorbate with proteins, causes covalent cross-linking and reduces the chaperone function of alpha-crystallin. We demonstrated that methylglyoxal (MGO), a metabolic alpha-dicarbonyl compound, modifies arginine residues in alpha-crystallin and enhances its chaperone function. We wanted to determine whether modification by MGO could protect alpha-crystallin from glycation-mediated cross-linking and loss of chaperone function. Our results show that MGO-modification of isolated bovine lens alpha-crystallin inhibits formation of pentosidine, a glycation-derived protein crosslink. Proteins in organ cultured rat lenses were similarly protected from pentosidine formation. Glycation by sugars and ascorbate resulted in almost complete loss of chaperone function of alpha-crystallin. Surprisingly, addition of MGO during or before glycation not only inhibited the loss of chaperone function, but it actually enhanced the chaperone function of alpha-crystallin. Together, these data suggest that in the aging lens, MGO inhibits glycation-mediated pentosidine synthesis and the loss of chaperone function of alpha-crystallin.
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Arrigo AP, Simon S, Gibert B, Kretz-Remy C, Nivon M, Czekalla A, Guillet D, Moulin M, Diaz-Latoud C, Vicart P. Hsp27 (HspB1) and alphaB-crystallin (HspB5) as therapeutic targets. FEBS Lett 2007; 581:3665-74. [PMID: 17467701 DOI: 10.1016/j.febslet.2007.04.033] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 04/11/2007] [Accepted: 04/15/2007] [Indexed: 12/11/2022]
Abstract
Hsp27 and alphaB-crystallin are molecular chaperones that are constitutively expressed in several mammalian cells, particularly in pathological conditions. These proteins share functions as diverse as protection against toxicity mediated by aberrantly folded proteins or oxidative-inflammation conditions. In addition, these proteins share anti-apoptotic properties and are tumorigenic when expressed in cancer cells. This review summarizes the current knowledge about Hsp27 and alphaB-crystallin and the implications, either positive or deleterious, of these proteins in pathologies such as neurodegenerative diseases, myopathies, asthma, cataracts and cancers. Approaches towards therapeutic strategies aimed at modulating the expression and/or the activities of Hsp27 and alphaB-crystallin are presented.
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Affiliation(s)
- André-Patrick Arrigo
- Laboratoire Stress, Chaperons et Mort Cellulaire, CNRS, UMR5534, Centre de Génétique Moléculaire et Cellulaire, Université Lyon 1, Bat. Gregor Mendel, 16 Rue Dubois, F-69622, Villeurbanne Cedex, France.
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15
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Abstract
Gastric mucosal cell death induced by non-steroidal anti-inflammatory drugs (NSAIDs) is suggested to be involved in NSAID-induced gastric lesions. Therefore, cellular factors that suppress this cell death are important for protection of the gastric mucosa from NSAIDs. When cells are exposed to various stressors, including NSAIDs, they induce a number of proteins, so-called stress proteins, in order to protect themselves against such stressors. Stress proteins contain cytosolic molecular chaperons (such as heat shock proteins), endoplasmic reticulum molecular chaperons (such as glucose-regulated proteins) and heme oxygenase-1. We recently showed that (i) these stress proteins are up-regulated by NSAIDs both in vitro and in vivo; (ii) these up-regulation make gastric mucosal cells resistant to NSAIDs in vitro; (iii) these up-regulation protects the gastric mucosa from NSAID-induced gastric lesions in vivo. In this review, I summarize these results and propose that non-toxic inducers of these stress proteins are therapeutically beneficial as anti-ulcer drugs.
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Affiliation(s)
- T Mizushima
- Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan.
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Tashiro J, Kikuchi S, Shinpo K, Kishimoto R, Tsuji S, Sasaki H. Role of p53 in neurotoxicity induced by the endoplasmic reticulum stress agent tunicamycin in organotypic slice cultures of rat spinal cord. J Neurosci Res 2007; 85:395-401. [PMID: 17131418 DOI: 10.1002/jnr.21120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The endoplasmic reticulum (ER) is important for maintaining the quality of cellular proteins. Various stimuli can disrupt ER homeostasis and cause the accumulation of unfolded or misfolded proteins, i.e., a state of ER stress. Recently, ER stress has been reported to play an important role in the pathogenesis of neurological disorders such as cerebral ischemia and neurodegenerative diseases, but its involvement in the spinal cord diseases has not been fully discussed. We conducted this study using tunicamycin (Tm) as an ER stress inducer for rat spinal cord in organotypic slice culture, a system that we have recently established. Tm was shown to induce ER stress by increased expression of GRP78. The viability rate of spinal cord neurons decreased in a dose-dependent manner with Tm treatment, and dorsal horn interneurons were more vulnerable to Tm-induced neurotoxicity. A p53 inhibitor significantly increased the viability of dorsal horn interneurons, and immunofluorescence studies showed nuclear accumulation of p53 in the dorsal horns of Tm-treated spinal cord slices. These findings suggest that p53 plays an important role in the killing of dorsal horn interneurons by Tm. In contrast, motor neurons were not protected by the p53 inhibitor, suggesting that the role of p53 may vary between different cell types. This difference might be a clue to the mechanism of the stress-response pathway and might also contribute to the potential application of p53 inhibitors for the treatment of spinal cord diseases, including amyotrophic lateral sclerosis.
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Affiliation(s)
- Jun Tashiro
- Department of Neurology, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Hokkaido, Japan.
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Shin EH, Bian S, Shim YB, Rahman MA, Chung KT, Kim JY, Wang JQ, Choe ES. Cocaine increases endoplasmic reticulum stress protein expression in striatal neurons. Neuroscience 2007; 145:621-30. [PMID: 17303341 DOI: 10.1016/j.neuroscience.2006.12.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Revised: 12/04/2006] [Accepted: 12/05/2006] [Indexed: 11/17/2022]
Abstract
Cocaine administration upregulates the levels of extracellular glutamate and dopamine in the striatum. Activation of the receptors alters calcium homeostasis in striatal neurons leading to the expression of the endoplasmic reticulum (ER) stress proteins. It was therefore hypothesized that cocaine upregulates the expression of the ER stress proteins, immunoglobulin heavy chain binding protein (BiP), Ire1alpha and perk via glutamate and dopamine receptor activation. A novel glutamate microbiosensor and Western immunoblot analyses were mainly performed to test the hypothesis in the rat dorsal striatum. The results showed that i.p. injection of repeated cocaine (20 mg/kg) for nine consecutive days significantly increased extracellular glutamate levels while acute cocaine injection did not. However, the immunoreactivities (IR) of the ER stress proteins in the dorsal striatum were significantly increased by either acute or repeated cocaine injections as compared with saline controls. Intrastriatal injection (i.s.) of the selective group I metabotropic glutamate receptor (mGluR) antagonist N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC; 25 nmol) or the mGluR5 subtype antagonist 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP; 2 and 25 nmol) significantly decreased repeated cocaine-induced increases in the IR of the ER stress proteins in the injected dorsal striatum. Similarly, the selective D1 antagonist (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 0.1 mg/kg, i.p.) or the N-methyl-d-aspartate antagonist dizocilpine/(5S,10R)-(+)-5-methyl-10,11-dihydro-5H-ibenzo[a,d]cyclohepten-5,10-imine maleate (MK801; 2 nmol, i.s.) decreased acute or repeated cocaine-induced the IR of the ER stress proteins in the dorsal striatum. These data suggest that cocaine upregulates expression of the ER stress proteins in striatal neurons via a mechanism involving activation of glutamate and dopamine receptors.
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MESH Headings
- Animals
- Cocaine/pharmacology
- Cocaine-Related Disorders/metabolism
- Cocaine-Related Disorders/physiopathology
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Dopamine Antagonists/pharmacology
- Dopamine Uptake Inhibitors/pharmacology
- Endoplasmic Reticulum/drug effects
- Endoplasmic Reticulum/metabolism
- Excitatory Amino Acid Antagonists/pharmacology
- Heat-Shock Proteins/drug effects
- Heat-Shock Proteins/metabolism
- Male
- Membrane Proteins/drug effects
- Membrane Proteins/metabolism
- Molecular Chaperones/drug effects
- Molecular Chaperones/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Protein Serine-Threonine Kinases/drug effects
- Protein Serine-Threonine Kinases/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine D1/drug effects
- Receptors, Dopamine D1/metabolism
- Receptors, Metabotropic Glutamate/drug effects
- Receptors, Metabotropic Glutamate/metabolism
- Receptors, N-Methyl-D-Aspartate/drug effects
- Receptors, N-Methyl-D-Aspartate/metabolism
- Stress, Physiological/chemically induced
- Stress, Physiological/metabolism
- Stress, Physiological/physiopathology
- Up-Regulation/drug effects
- Up-Regulation/physiology
- eIF-2 Kinase/drug effects
- eIF-2 Kinase/metabolism
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Affiliation(s)
- E H Shin
- Department of Biology and Center for Innovative BioPhysio Sensor Technology, Pusan National University, 30 Jangjeon-dong, Kumjeong-gu, C6-311, Pusan 609-735, Korea
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18
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Shacka JJ, Lu J, Xie ZL, Uchiyama Y, Roth KA, Zhang J. Kainic acid induces early and transient autophagic stress in mouse hippocampus. Neurosci Lett 2006; 414:57-60. [PMID: 17223264 PMCID: PMC1839881 DOI: 10.1016/j.neulet.2006.12.025] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 12/05/2006] [Accepted: 12/06/2006] [Indexed: 01/25/2023]
Abstract
Kainic acid (KA) treatment is a well-established model of hippocampal neuron death mediated in large part by KA receptor-induced excitotoxicity. KA-induced, delayed neuron death has been shown previously to follow the induction of seizures and exhibit characteristics of both apoptosis and necrosis. Growing evidence supports a role of autophagic stress-induced death of neurons in several in vitro and in vivo models of neuron death and neurodegeneration. However, whether autophagic stress also plays a role in KA-induced excitotoxicity has not been previously investigated. To examine whether KA alters the levels of proteins associated with or known to regulate the formation of autophagic vacuoles, we isolated hippocampal extracts from control mice and in mice following 2-16 h KA injection. KA induced a significant increase in the amount of LC3-II, a specific marker of autophagic vacuoles, at 4-6h following KA, which indicates a transient induction of autophagic stress. Levels of autophagy-associated proteins including ATG5 (conjugated to ATG12), ATG6 and ATG7 did not change significantly after treatment with KA. However, ratios of phospho-mTOR/mTOR were elevated from 6 to 16 h, and ratios of phospho-Akt/Akt were elevated at 16 h following KA treatment, suggesting a potential negative feedback loop to inhibit further stimulation of autophagic stress. Together these data indicate the transient induction of autophagic stress by KA which may serve to regulate excitotoxic death in mouse hippocampus.
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Affiliation(s)
- John J. Shacka
- Division of Neuropathology, Dept. of Pathology, University of Alabama at Birmingham
| | - Jun Lu
- Division of Neuropathology, Dept. of Pathology, University of Alabama at Birmingham
| | - Zuo-Lei Xie
- Division of Neuropathology, Dept. of Pathology, University of Alabama at Birmingham
| | - Yasuo Uchiyama
- Dept. Cell Biology and Neurosciences, Osaka University, Osaka, Japan
| | - Kevin A. Roth
- Division of Neuropathology, Dept. of Pathology, University of Alabama at Birmingham
| | - Jianhua Zhang
- Division of Neuropathology, Dept. of Pathology, University of Alabama at Birmingham
- *Corresponding author: Jianhua Zhang, Ph.D., Division of Neuropathology, Department of Pathology, University of Alabama at Birmingham, SC 961, 1530 3rd Ave S, Birmingham, AL 35294-0017, Phone: 205-996-5153; Fax: 205-934-6700;
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19
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Kim Y, Lillo AM, Steiniger SCJ, Liu Y, Ballatore C, Anichini A, Mortarini R, Kaufmann GF, Zhou B, Felding-Habermann B, Janda KD. Targeting heat shock proteins on cancer cells: selection, characterization, and cell-penetrating properties of a peptidic GRP78 ligand. Biochemistry 2006; 45:9434-44. [PMID: 16878978 DOI: 10.1021/bi060264j] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptidic ligands can be used for specific cell targeting and the delivery of payloads into the target cell. Here we describe the screening of a pool of cyclic peptide phage display libraries using whole-cell panning against human melanoma cell line Me6652/4. This strategy resulted in the selection of the cyclic 13-mer Pep42, CTVALPGGYVRVC, which showed preferential internalization into melanoma cell line Me6652/4 versus the reference cell line Me6652/56. This translocation is a receptor-mediated process that does not require electrostatic interactions nor does it involve transfer to the lysosomal compartment. The cellular receptor for Pep42 was identified as the surface membrane form of glucose-regulated protein 78 (GRP78), a member of the heat shock protein family and a marker on malignant cancer cells. The cellular uptake and intracellular trafficking of Pep42-Quantum Dot conjugates was monitored by confocal laser microscopy, and colocalization within the endoplasmic reticulum was observed. The uptake of Pep42 could be blocked by a monoclonal antibody against the identified receptor. Furthermore, Pep42 was shown to target specifically GRP78-expressing cancer cells. The in vitro cytotoxicity of a Pep42-Taxol conjugate was evaluated by flow cytometry wherein the conjugate was shown to induce apoptosis and was more effective in promoting programmed cell death in Me6652/4 cells. In summary, the data presented suggest that cyclic peptide Pep42 might be a powerful tool in the construction of drug conjugates designed to selectively kill malignant cancer cells.
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Affiliation(s)
- Youngsoo Kim
- The Skaggs Institute for Chemical Biology and Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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20
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Ramya TNC, Surolia N, Surolia A. 15-Deoxyspergualin modulates Plasmodium falciparum heat shock protein function. Biochem Biophys Res Commun 2006; 348:585-92. [PMID: 16884692 DOI: 10.1016/j.bbrc.2006.07.082] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 07/18/2006] [Indexed: 10/24/2022]
Abstract
Heat shock proteins are essential for the survival of all cells. The C-terminal EEVD motif of Hsp70 has previously been implicated in binding 15-deoxyspergualin (DSG), an immunosuppressant with antimalarial activity whose mechanism of action is uncertain. We report the cloning, overexpression, and characterization of three members of the heat shock family, PfHsp70-1 (an Hsp70 protein with a C-terminal EEVD motif), PfHsp70-2 (an Hsp70 protein without the EEVD motif), and PfHsp70 interacting protein. The chaperone activity of PfHsp70-1, and PfHsp70-2 was enhanced by ATP and by PfHip. Interestingly, while binding of protein substrates to PfHsp70-1, PfHsp70-2 and PfHip was unaffected in the presence of DSG, the ATP enhanced chaperone activity of PfHsp70-1 but not PfHsp70-2 was stimulated further by DSG. Our finding suggests that the binding partner of DSG in the parasite cellular milieu is PfHsp70-1 and paves the way for the elucidation of the mechanism of antimalarial action of DSG.
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Affiliation(s)
- T N C Ramya
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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21
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22
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Yoshida I, Monji A, Tashiro KI, Nakamura KI, Inoue R, Kanba S. Depletion of intracellular Ca2+ store itself may be a major factor in thapsigargin-induced ER stress and apoptosis in PC12 cells. Neurochem Int 2006; 48:696-702. [PMID: 16481070 DOI: 10.1016/j.neuint.2005.12.012] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 12/13/2005] [Indexed: 11/24/2022]
Abstract
The mechanisms of intracellular calcium store depletion and store-related Ca(2+) dysregulation in relation to apoptotic cell death in PC12 cells were investigated at physiological temperatures with a leak-resistant fluorescent indicator dye Fura-PE3/AM by a cooled CCD imaging analysis system. Electron microscopic observations have shown thapsigargin (TG; 100 nM)-induced apoptosis in PC12 cells. Thorough starvation of stored Ca(2+) by BAPTA/AM (50 microM), or La(3+) (100 microM) enhanced while dantrolene (100 microM) attenuated the TG-induced apoptosis by preventing a calcium release from internal stores. An immunoblotting analysis revealed an enhanced expression of GRP78, the hallmark of endoplasmic reticulum (ER) stress when cells were treated by TG along with BAPTA/AM. These results indicate that the depletion of the intracellular Ca(2+) stores itself induces the ER stress and apoptosis in PC12 cells without any involvement of the capacitative calcium entry (CCE) or a sustained elevation of intracellular Ca(2+) concentrations ([Ca(2+)](i)).
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Affiliation(s)
- Ichiro Yoshida
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
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23
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Turner MJ, Delay ML, Bai S, Klenk E, Colbert RA. HLA–B27 up-regulation causes accumulation of misfolded heavy chains and correlates with the magnitude of the unfolded protein response in transgenic rats: Implications for the pathogenesis of spondylarthritis-like disease. ACTA ACUST UNITED AC 2006; 56:215-23. [PMID: 17195225 DOI: 10.1002/art.22295] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE HLA-B27 is implicated in the pathogenesis of spondylarthritis (SpA), yet the molecular mechanisms are incompletely defined. HLA-B27 misfolding has been associated with endoplasmic reticulum stress and activation of the unfolded protein response (UPR) in macrophages from HLA-B27/human beta(2)-microglobulin-transgenic (B27-transgenic) rats. This study was performed to assess the mechanisms that drive activation of the HLA-B27-induced UPR and to determine whether splenocytes respond in a similar manner. METHODS Splenocytes were isolated and bone marrow macrophages were derived from B27-transgenic and wild-type rats. Cells were treated for up to 24 hours with cytokines that induce class I major histocompatibility complex expression. HLA-B27 expression and misfolding were assessed by real-time reverse transcription-polymerase chain reaction, flow cytometry, and immunoblotting. Activation of the UPR was measured by quantifying UPR target gene expression and X-box binding protein 1 messenger RNA (mRNA) splicing. RESULTS HLA-B27 mRNA up-regulation was accompanied by a dramatic increase in the accumulation of misfolded heavy chains and preceded robust activation of the UPR in macrophages. When macrophages were treated with various cytokines, the magnitude of the UPR correlated strongly with the degree of HLA-B27 up-regulation. In contrast, B27-transgenic splenocytes exhibited only low-level differences in the expression of UPR target genes after exposure to interferon-gamma or concanavalin A, which resulted in minimal HLA-B27 up-regulation. CONCLUSION These results suggest that HLA-B27-associated activation of the UPR in macrophages is attributable to the accumulation of misfolded heavy chains, and that certain cell types may be more susceptible to the effects of HLA-B27 misfolding. Strategies that eliminate HLA-B27 up-regulation and/or the accumulation of misfolded heavy chains may be useful in evaluating the role of these events in the pathogenesis of SpA.
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Affiliation(s)
- Matthew J Turner
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
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24
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Yamada K, Goto S, Kaji R, Kuratsu JI. Modulation of torsinA expression in the globus pallidus internus is associated with levodopa-induced dyskinesia in hemiparkinsonian rats. Neurosci Lett 2005; 396:62-6. [PMID: 16325337 DOI: 10.1016/j.neulet.2005.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Revised: 10/14/2005] [Accepted: 11/04/2005] [Indexed: 11/28/2022]
Abstract
TorsinA is the causative protein of DYT1 dystonia, a major representative of hyperkinetic movement disorders. In this study, the distribution of torsinA was investigated in the basal ganglia of hemiparkinsonian rats with or without levodopa-induced dyskinesia (LID). Two months after 6-hydroxydopamine (OHDA) treatment, Wistar-albino rats were subjected to intermittent intraperitoneal injection of levodopa/benserazid (LID-group, n=5) or vehicle (control, n=5) for 21 days. Immunohistochemical analysis disclosed that in the caudal portion of the entopeduncular nucleus (EP), homologous to the globus pallidus internus (GPi) in primates, on the parkinsonian side, there was a significant decrease of torsinA-immunopositive neurons in rats with LID, but not in those without LID. However, Nissl-staining showed no loss of GPi neurons in rats with LID. In both groups, there was no significant difference between ipsi- and contralateral sides with respect to the density of torsinA-positive neuronal cells in the striatum, globus pallidus externus, and subthalamic nucleus. Ours are the first data to demonstrate the specific modulation of torsinA expression in the basal ganglia of the hyperkinesia model, suggesting that GPi neurons containing torsinA possess pathologic plasticity for LID.
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Affiliation(s)
- Kazumichi Yamada
- Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan
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Shao L, Sun X, Xu L, Young LT, Wang JF. Mood stabilizing drug lithium increases expression of endoplasmic reticulum stress proteins in primary cultured rat cerebral cortical cells. Life Sci 2005; 78:1317-23. [PMID: 16236328 DOI: 10.1016/j.lfs.2005.07.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Accepted: 07/05/2005] [Indexed: 11/19/2022]
Abstract
The mood stabilizing drug lithium is a highly effective treatment for bipolar disorder. Previous studies in our laboratory found that chronic treatment with the mood stabilizing drug valproate in rat brain increased the expression of endoplasmic reticulum (ER) stress proteins GRP78, GRP94 and calreticulin. We report here that in primary cultured rat cerebral cortical cells, expression of GRP78, GRP94 and calreticulin are increased not only by valproate, but also by lithium after chronic treatment for 1 week at therapeutically relevant concentrations. However, two other mood stabilizing drugs carbamazepine and lamotrigine had no effect on expression of GRP78, GRP94 or calreticulin. Chronic treatment with lithium for 1 week increased both mRNA and protein levels of ER stress proteins. In contrast to a classic GRP78 inducer thapsigargin, an inhibitor of the ER Ca2+ -ATPase, chronic treatment with lithium or valproate for 1 week modestly increased GRP78 expression in neuronal cells, had no effect on basal intracellular free Ca2+ concentration and does not induce cell death. These results indicate that lithium and valproate may increase expression of GRP78, GRP94 and calreticulin in primary cultured rat cerebral cortical cells without causing cell damage. These results also suggest that the mechanism of GRP78 increase induced by lithium and valproate may be different from that of thapsigargin.
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Affiliation(s)
- Li Shao
- The Vivian Rakoff Mood Disorders Laboratory, Centre for Addiction and Mental Health, 250 College Street, Room 1105, Toronto, Ontario, Canada, M5T 1R8
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26
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Aberg V, Hedenström M, Pinkner JS, Hultgren SJ, Almqvist F. C-Terminal properties are important for ring-fused 2-pyridones that interfere with the chaperone function in uropathogenic E. coli. Org Biomol Chem 2005; 3:3886-92. [PMID: 16240004 DOI: 10.1039/b509376g] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Virulence-associated organelles, termed pili or fimbriae, are assembled via the highly conserved chaperone-usher pathway in a vast number of pathogenic bacteria. Substituted bicyclic 2-pyridones, pilicides, inhibit pilus formation, possibly by interfering with the active site residues Arg8 and Lys112 of chaperones in uropathogenic E. coli. In this article we describe the synthesis and evaluation of nine analogues of a biologically active pilicide. Derivatization was performed with respect to its C-terminal features and the affinities for the chaperone PapD were studied with 1H relaxation-edited NMR spectroscopy. It could be concluded that the carboxylic acid functionality and also its spatial location was important for binding. In all cases, binding was significantly reduced or even abolished when the carboxylic acid was replaced by other substituents. In addition, in vivo results from a hemagglutination assay are presented where the derivatives have been evaluated for their ability to inhibit pilus formation in uropathogenic E. coli.
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Affiliation(s)
- Veronica Aberg
- Organic Chemistry, Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
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Abstract
CFTR mutations cause defects of CFTR protein production and function by different molecular mechanisms. Mutations can be classified according to the mechanisms by which they disrupt CFTR function. This understanding of the different molecular mechanisms of CFTR dysfunction provides the scientific basis for the development of targeted drugs for mutation-specific therapy of cystic fibrosis (CF). Class I mutations are nonsense mutations that result in the presence of a premature stop codon that leads to the production of unstable mRNA, or the release from the ribosome of a short, truncated protein that is not functional. Aminoglycoside antibiotics can suppress premature termination codons by disrupting translational fidelity and allowing the incorporation of an amino acid, thus permitting translation to continue to the normal termination of the transcript. Class II mutations cause impairment of CFTR processing and folding in the Golgi. As a result, the mutant CFTR is retained in the endoplasmic reticulum (ER) and eventually targeted for degradation by the quality control mechanisms. Chemical and molecular chaperones such as sodium-4-phenylbutyrate can stabilize protein structure, and allow it to escape from degradation in the ER and be transported to the cell membrane. Class III mutations disrupt the function of the regulatory domain. CFTR is resistant to phosphorylation or adenosine tri-phosphate (ATP) binding. CFTR activators such as alkylxanthines (CPX) and the flavonoid genistein can overcome affected ATP binding through direct binding to a nucleotide binding fold. In patients carrying class IV mutations, phosphorylation of CFTR results in reduced chloride transport. Increases in the overall cell surface content of these mutants might overcome the relative reduction in conductance. Alternatively, restoring native chloride pore characteristics pharmacologically might be effective. Activators of CFTR at the plasma membrane may function by promoting CFTR phosphorylation, by blocking CFTR dephosphorylation, by interacting directly with CFTR, and/or by modulation of CFTR protein-protein interactions. Class V mutations affect the splicing machinery and generate both aberrantly and correctly spliced transcripts, the levels of which vary among different patients and among different organs of the same patient. Splicing factors that promote exon inclusion or factors that promote exon skipping can promote increases of correctly spliced transcripts, depending on the molecular defect. Inconsistent results were reported regarding the required level of corrected or mutated CFTR that had to be reached in order to achieve normal function.
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Affiliation(s)
- Eitan Kerem
- Department of Pediatrics and Cystic Fibrosis Center, Hadassah University Hospital, Jerusalem, Israel.
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Lane-Guermonprez L, Morot-Gaudry-Talarmain Y, Meunier FM, O'Regan S, Onofri F, Le Caer JP, Benfenati F. Synapsin associates with cyclophilin B in an ATP- and cyclosporin A-dependent manner. J Neurochem 2005; 93:1401-11. [PMID: 15935056 DOI: 10.1111/j.1471-4159.2005.03125.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Immunophilins are ubiquitous enzymes responsible for proline isomerisation during protein synthesis and for the chaperoning of several membrane proteins. These activities can be blocked by the immunosuppressants cyclosporin A, FK506 and rapamycin. It has been shown that all three immunosuppressants have neurotrophic activity and can modulate neurotransmitter release, but the molecular basis of these effects is currently unknown. Here, we show that synapsin I, a synaptic vesicle-associated protein, can be purified from Torpedo cholinergic synaptosomes through its affinity to cyclophilin B, an immunophilin that is particularly abundant in brain. The interaction is direct and conserved in mammals, and shows a dissociation constant of about 0.5 microM in vitro. The binding between the two proteins can be disrupted by cyclosporin A and inhibited by physiological concentrations of ATP. Furthermore, cyclophilin B co-localizes with synapsin I in rat synaptic vesicle fractions and its levels in synaptic vesicle-containing fractions are decreased in synapsin knockout mice. These results suggest that immunophilins are involved in the complex protein networks operating at the presynaptic level and implicate the interaction between cyclophilin B and synapsins in presynaptic function.
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Affiliation(s)
- Lydie Lane-Guermonprez
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS UPR 9040, Gif sur Yvette Cedex, France
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Choo SJ, Park HR, Ryoo IJ, Kim JP, Yun BS, Kim CJ, Shin-ya K, Yoo ID. Deoxyverrucosidin, a novel GRP78/BiP down-regulator, produced by Penicillium sp. J Antibiot (Tokyo) 2005; 58:210-3. [PMID: 15895531 DOI: 10.1038/ja.2005.26] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glucose-regulated protein 78 (GRP78) resides in endoplasmic reticulum (ER) and plays a role in protecting tumor cells against the toxic effects of anticancer agents. During the search for down-regulators of GRP78 using a reporter gene (luciferase) assay system, we isolated a novel compound designated as deoxyverrucosidin (1), a congener of verrucosidin (2), from Penicillium sp. and identified it as a down-regulator of the grp78 gene. The structure of 1 was determined by mainly ESI-mass and two-dimensional NMR spectra. 1 dose-dependently inhibited the expression of GRP78 promoter with an IC50 of 30 nM.
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Affiliation(s)
- Soo-Jin Choo
- Laboratory of Antioxidants, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Korea
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Tissing WJE, Meijerink JPP, den Boer ML, Brinkhof B, Pieters R. mRNA expression levels of (co)chaperone molecules of the glucocorticoid receptor are not involved in glucocorticoid resistance in pediatric ALL. Leukemia 2005; 19:727-33. [PMID: 15759037 DOI: 10.1038/sj.leu.2403681] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Resistance to glucocorticoids (GC) is an important adverse risk factor in the treatment of acute lymphoblastic leukemia (ALL). To induce apoptosis, GC bind to the GC receptor (GR), which is regulated by various (co)chaperone proteins such as heat-shock protein 70 (HSP-70), HSP-40, HIP (HSP-70-interacting protein), BAG-1 (BCL-2-associated gene product-1), HOP (HSP-70/HSP-90-Organizing protein), HSP-90, P-23, FKBP-51, FKBP-52 and CYP-40. In this study, we tested the hypothesis that mRNA expression levels of these molecules are determinants of GC resistance in childhood ALL. In all, 20 children with ALL cells in vitro sensitive to prednisolone (LC(50) < 0.1 microg/ml) were compared each with a resistant patient (LC(50) >150 mug/ml), matched for immunophenotype, age and white blood cell count. mRNA expression levels of the (co)chaperone molecules were measured by quantitative real-time RT-PCR and normalized to GAPDH and RNaseP levels. In vitro resistance to prednisolone was measured by MTT assay. HSP-90 mRNA expression levels were 2000-fold higher as compared to HSP-70. Using matched pair analysis, mRNA expression levels of the various (co)chaperone molecules were not significantly different between in vitro-sensitive and -resistant patients. GC resistance in childhood ALL cannot be attributed to different mRNA expression levels of the investigated (co)chaperone molecules involved in GC binding and transport to the nucleus.
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Affiliation(s)
- W J E Tissing
- Division of Pediatric Oncology/Hematology, Erasmus MC-Sophia Childrens Hospital, University Medical Center Rotterdam, The Netherlands
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31
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Bali P, Pranpat M, Bradner J, Balasis M, Fiskus W, Guo F, Rocha K, Kumaraswamy S, Boyapalle S, Atadja P, Seto E, Bhalla K. Inhibition of histone deacetylase 6 acetylates and disrupts the chaperone function of heat shock protein 90: a novel basis for antileukemia activity of histone deacetylase inhibitors. J Biol Chem 2005; 280:26729-34. [PMID: 15937340 DOI: 10.1074/jbc.c500186200] [Citation(s) in RCA: 613] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hydroxamic acid (HAA) analogue pan-histone deacetylase (HDAC) inhibitors (HDIs) LAQ824 and LBH589 have been shown to induce acetylation and inhibit the ATP binding and chaperone function of heat shock protein (HSP) 90. This promotes the polyubiquitylation and degradation of the pro-growth and pro-survival client proteins Bcr-Abl, mutant FLT-3, c-Raf, and AKT in human leukemia cells. HDAC6 is a member of the class IIB HDACs. It is predominantly cytosolic, microtubule-associated alpha-tubulin deacetylase that is also known to promote aggresome inclusion of the misfolded polyubiquitylated proteins. Here we demonstrate that in the Bcr-abl oncogene expressing human leukemia K562 cells, HDAC6 can be co-immunoprecipitated with HSP90, and the knock-down of HDAC6 by its siRNA induced the acetylation of HSP90 and alpha-tubulin. Depletion of HDAC6 levels also inhibited the binding of HSP90 to ATP, reduced the chaperone association of HSP90 with its client proteins, e.g. Bcr-Abl, and induced polyubiquitylation and partial depletion of Bcr-Abl. Conversely, the ectopic overexpression of HDAC6 inhibited LAQ824-induced acetylation of HSP90 and alpha-tubulin and reduced LAQ824-mediated depletion of Bcr-Abl, AKT, and c-Raf. Collectively, these findings indicate that HDAC6 is also an HSP90 deacetylase. Targeted inhibition of HDAC6 leads to acetylation of HSP90 and disruption of its chaperone function, resulting in polyubiquitylation and depletion of pro-growth and pro-survival HSP90 client proteins including Bcr-Abl. Depletion of HDAC6 sensitized human leukemia cells to HAA-HDIs and proteasome inhibitors.
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Affiliation(s)
- Purva Bali
- Department of Interdisciplinary Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida 33612, USA
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Abstract
Benzoquinoid ansamycins can downregulate molecules which are chaperoned by heat shock protein (Hsp90), including numerous tyrosine kinases, steroid receptors, and cell cycle regulatory kinases. 17allylaminol7demethoxygeldanamycin (17AAG) has entered the clinic, but 17dimethyl-aminoethylaminogeldanamycin (17DMA) has emerged as an analog with potential preferential pharmaceutical features.
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Affiliation(s)
- E A Sausville
- Developmental Therapeutics Program, National Cancer Institute, Bethesda, MD, USA.
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Murphy PJM. Regulation of glucocorticoid receptor steroid binding and trafficking by the hsp90/hsp70-based chaperone machinery: implications for clinical intervention. Leukemia 2005; 19:710-2. [PMID: 15759036 DOI: 10.1038/sj.leu.2403687] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jinn TL, Chiu CC, Song WW, Chen YM, Lin CY. Azetidine-induced accumulation of class I small heat shock proteins in the soluble fraction provides thermotolerance in soybean seedlings. Plant Cell Physiol 2004; 45:1759-67. [PMID: 15557296 DOI: 10.1093/pcp/pch193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Accumulation of class I small heat shock proteins (sHSPs) is induced by the proline analog, azetidine-2-carboxylic acid (Aze) in soybean seedlings to a level similar to that induced by exposure to 40 degrees C. However, only the treatment with 10 mM Aze for 6 h and subsequently with 10 mM proline for 24 h protected the seedlings from damage during subsequent exposure to 45 degrees C as assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining. A chaperone activity assay showed that the purified class I sHSPs induced by Aze were functional in vitro and protected proteins from thermal denaturation. Amino acid composition analysis indicated that Aze was not incorporated into de novo synthesized class I sHSPs. Accumulation of class I sHSPs in the soluble post-ribosomal supernatant fraction was found to be important for acquisition of thermotolerance. We suggest that both the accumulation of class I sHSPs and their presence in the soluble fraction are important for establishment of thermotolerance.
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Affiliation(s)
- Tsung-Luo Jinn
- Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan, R.O.C
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35
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Gausdal G, Gjertsen BT, Fladmark KE, Demol H, Vandekerckhove J, Døskeland SO. Caspase-dependent, geldanamycin-enhanced cleavage of co-chaperone p23 in leukemic apoptosis. Leukemia 2004; 18:1989-96. [PMID: 15483679 DOI: 10.1038/sj.leu.2403508] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Co-chaperone p23 is a component of the heat-shock protein (Hsp)90 multiprotein-complex and is an important modulator of Hsp90 activity. Hsp90 client proteins involved in oncogenic survival signaling are frequently mutated in leukemia, and the integrity of the Hsp90 complex could therefore be important for leukemic cell survival. We demonstrate here that p23 is cleaved to a stable 17 kDa fragment in leukemic cell lines treated with commonly used chemotherapeutic drugs. The cleavage of p23 paralleled the activation of procaspase-7 and -3 and was suppressed by the caspase-3/-7 inhibitor DEVD-FMK. In vitro translated 35S-p23 (in reticulocyte lysate) was cleaved at D142 and D145 by caspase-7 and -3. Cleavage of p23 occurred in caspase-3-deficient MCF-7 cells, suggesting a role for caspase-7 in intact cells. The Hsp90 inhibitor geldanamycin enhanced caspase-dependent p23 cleavage both in vitro and in intact cells. Geldanamycin also enhanced anthracycline-induced caspase activation and apoptosis. We conclude that p23 is a prominent target in leukemic cell apoptosis. Geldanamycin enhanced p23 cleavage both by rendering p23 more susceptible to caspases and by enhancing chemotherapy-induced caspase activation. These findings underscore the importance of the Hsp90-complex in antileukemic treatment, and suggest that p23 may have a role in survival signaling.
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Affiliation(s)
- G Gausdal
- Department of Biomedicine, Section of Anatomy and Cell Biology and PROBE, University of Bergen, Norway
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36
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Kontargiris E, Kolettas E, Vadalouca A, Trougakos IP, Gonos ES, Kalfakakou V. Ectopic expression of clusterin/apolipoprotein J or Bcl-2 decreases the sensitivity of HaCaT cells to toxic effects of ropivacaine. Cell Res 2004; 14:415-22. [PMID: 15538973 DOI: 10.1038/sj.cr.7290242] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Local anesthetics inhibit cell proliferation and induce apoptosis in various cell types. Ropivacaine, a unique, novel tertiary amine-type anesthetic, was shown to inhibit the proliferation of several cell types including keratinocytes. We found that Ropivacaine could inhibit the proliferation and induce apoptosis in an immortalized human keratinocyte line, HaCaT, in a dose- and time-dependent manner and with the deprivation of serum. The dose-dependent induction of apoptosis by ropivacaine was demonstrated by DNA fragmentation analysis and the proteolytic cleavage of a caspase-3 substrate-poly (ADP-ribose) polymerase (PARP). In addition, ropivacaine downregulated the expression of clusterin/ apoliporotein J, a protein with anti-apoptotic properties, in a dose-dependent manner, which well correlated with the induction of apoptosis of HaCaT cells. To investigate the role of clusterin/apoliporotein J in ropivacaine-induced apoptosis, HaCaT cells overexpressing clusterin/apoliporotein J were generated and compared to cells expressing the well established anti-apoptotic Bcl-2 protein. Ectopic overexpression of the secreted form of clusterin/apoliporotein J or Bcl-2 decreased the sensitivity of HaCaT cells to toxic effects of ropivacaine as demonstrated by DNA fragmentation, the proteolytic cleavage of PARP and by a reduction in procaspase-3 expression. Furthermore, the downregulation of endogenous clusterin/apolipoprotein J levels by ropivacaine suggested that this might be one mechanism by which ropivacaine induced cell death in HaCaT cells. In conclusion, the ability of ropivacaine to induce antiproliferative responses and to suppress the expression of the anti-apoptotic protein clusterin/apolipoprotein J, combined with previously reported anti-inflammatory activity and analgesic property of the drug, suggests that ropivacaine may have potential utility in the local treatment of tumors.
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Affiliation(s)
- Evangelos Kontargiris
- Laboratory of Experimental Physiology, University of Ioannina Medical School, 45110 Ioannina, Greece
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Maeda T, Sugiura R, Kita A, Saito M, Deng L, He Y, Yabin L, Fujita Y, Takegawa K, Shuntoh H, Kuno T. Pmr1, a P-type ATPase, and Pdt1, an Nramp homologue, cooperatively regulate cell morphogenesis in fission yeast: the importance of Mn2+ homeostasis. Genes Cells 2004; 9:71-82. [PMID: 14723709 DOI: 10.1111/j.1356-9597.2004.00699.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Schizosaccharomyces pombe pmr1+ gene is homologous to Saccharomyces cerevisiae PMR1 gene, which encodes the P-type Ca2+/Mn2+-ATPase. Addition of Mn2+, as well as Ca2+, to the medium induced pmr1+ gene expression in a calcineurin-dependent manner. The pmr1 knockout (Deltapmr1) cells exhibited hypersensitivity to EGTA. A screen for high gene dosage-suppressors of the EGTA-hypersensitive phenotype of Deltapmr1 led to the identification of pdt1+ gene, which encodes an Nramp-related metal transporter. The Deltapmr1 cells showed round cell morphology. Although Deltapdt1 cells appeared normal in the regular medium, it showed round cell morphology similar to that of the Deltapmr1 cells when Mn2+ was removed from the medium. The removal of Mn2+ also exacerbated the round morphology of the Deltapmr1 cells. The Deltapmr1Deltapdt1 double mutants grew very slowly and showed extremely aberrant cell morphology with round, enlarged and depolarized shape. The addition of Mn2+, but not Ca2+, to the medium completely suppressed the morphological defects, while both Mn2+ and Ca2+ markedly improved the slow growth of the double mutants. These results suggest that Pmr1 and Pdt1 cooperatively regulate cell morphogenesis through the control of Mn2+ homeostasis, and that calcineurin functions as a Mn2+ sensor as well as a Mn2+ homeostasis regulator.
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Affiliation(s)
- Takuya Maeda
- Division of Molecular Pharmacology and Pharmacogenomics, Department of Genome Sciences, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
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Lim M, McKenzie K, Floyd AD, Kwon E, Zeitlin PL. Modulation of ΔF508 Cystic Fibrosis Transmembrane Regulator Trafficking and Function with 4-Phenylbutyrate and Flavonoids. Am J Respir Cell Mol Biol 2004; 31:351-7. [PMID: 15191910 DOI: 10.1165/rcmb.2002-0086oc] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Over 70% of patients with cystic fibrosis have the DeltaF508 mutation. This protein is a partially functional chloride (Cl-) channel that is prematurely degraded in the endoplasmic reticulum. Specific members of the flavonoid class of compounds have been shown to increase Cl- conductance of wild-type and DeltaF508 cystic fibrosis transmembrane regulator (CFTR). Although flavonoid effects on CFTR processing are unknown, evidence of effects on heat shock proteins, specifically those that have been shown to interact with CFTR, led us to believe that there would be an effect on CFTR processing through modulation of CFTR-chaperone interactions. We sought to determine (i) the effect of apigenin, genistein, kaempferol, and quercetin on CFTR processing in IB3-1 cells (F508/W1282X) and (ii) whether sequential treatment with 4-phenylbutyrate (4-PBA) to increase CFTR processing and flavonoid to directly stimulate CFTR would increase Cl- conductance. Our results show no significant effect on CFTR processing as measured by immunoblotting with 1 microM or 5 microM of apigenin, genistein, kaempferol, or quercetin. However, despite no effect on CFTR processing as determined by immunoblot, immunofluorescence demonstrated a favorable change in the intracellular distribution of CFTR with 24 h treatments of apigenin, kaempferol, and genistein. Furthermore, we observed an increase in Cl- conductance as measured by Cl- efflux in cells that were treated for 24 h with 4-PBA and then assayed with forskolin and 1 microM or 5 microM genistein, and also with cells treated for 24 h with either 4-PBA, 5 microM apigenin, or 1 microM quercetin. Thus, a combination of chronic treatment with 4-PBA or select flavonoids, followed by acute flavonoid exposure, may be beneficial in cystic fibrosis.
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Affiliation(s)
- Meerana Lim
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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39
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O'Meara SJ, Kinsella BT. Investigation of the effect of the farnesyl protein transferase inhibitor R115777 on isoprenylation and intracellular signalling by the prostacyclin receptor. Br J Pharmacol 2004; 143:318-30. [PMID: 15339863 PMCID: PMC1575341 DOI: 10.1038/sj.bjp.0705956] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The human (h) and mouse (m) prostacyclin receptors (IPs) undergo isoprenylation through attachment of a C-15 farnesyl moiety within their conserved carboxyl terminal -CSLC sequences. Herein, the effects of a novel farnesyl transferase inhibitor R115777 on signalling by the hIP and mIP, overexpressed in human embryonic kidney 293 cells, and by the hIP endogenously expressed in human erythroleukaemia cells were investigated. R115777 significantly impaired IP-mediated cyclic AMP generation (IC(50) 0.37-0.60 nm) and intracellular calcium ([Ca(2+)](i)) mobilization (IC(50) 37-65 nm), but had no effect on signalling by the control nonisoprenylated beta(2) adrenergic receptor or the alpha or beta isoforms of the human thromboxane A(2) receptor (TP). Additionally, R115777 significantly reduced IP-mediated cross-desensitization of signalling by the TP alpha, but not by the TP beta, isoform of the human TP and impaired the farnesylation-dependent processing of the chaperone HDJ-2 protein (IC(50) 4.5 nm). Furthermore, R115777 fully impaired isoprenylation of both the Ha-Ras(WT) and Ha-Ras(CSLC) in vitro and in whole cells confirming that, unlike N-Ras and Ki-Ras, the -CSLC motif associated with the IP cannot support alternative geranylgeranylation in the presence of R115777 and does not act as a substrate for geranylgeranyl transferase 1 in vitro or in whole cells. In conclusion, these data confirm that R115777 potently impairs IP isoprenylation and signalling, and suggest that clinically it may not only target Ras proteins but may also disrupt IP isoprenylation, events which could impact on physiologic processes in which prostacyclin and its receptor are implicated.
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Affiliation(s)
- Sarah J O'Meara
- Department of Biochemistry, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - B Therese Kinsella
- Department of Biochemistry, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
- Author for correspondence:
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40
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Zhang W, Hirshberg M, McLaughlin SH, Lazar GA, Grossmann JG, Nielsen PR, Sobott F, Robinson CV, Jackson SE, Laue ED. Biochemical and structural studies of the interaction of Cdc37 with Hsp90. J Mol Biol 2004; 340:891-907. [PMID: 15223329 DOI: 10.1016/j.jmb.2004.05.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 05/07/2004] [Accepted: 05/11/2004] [Indexed: 11/18/2022]
Abstract
The heat shock protein Hsp90 plays a key, but poorly understood role in the folding, assembly and activation of a large number of signal transduction molecules, in particular kinases and steroid hormone receptors. In carrying out these functions Hsp90 hydrolyses ATP as it cycles between ADP- and ATP-bound forms, and this ATPase activity is regulated by the transient association with a variety of co-chaperones. Cdc37 is one such co-chaperone protein that also has a role in client protein recognition, in that it is required for Hsp90-dependent folding and activation of a particular group of protein kinases. These include the cyclin-dependent kinases (Cdk) 4/6 and Cdk9, Raf-1, Akt and many others. Here, the biochemical details of the interaction of human Hsp90 beta and Cdc37 have been characterised. Small angle X-ray scattering (SAXS) was then used to study the solution structure of Hsp90 and its complexes with Cdc37. The results suggest a model for the interaction of Cdc37 with Hsp90, whereby a Cdc37 dimer binds the two N-terminal domain/linker regions in an Hsp90 dimer, fixing them in a single conformation that is presumably suitable for client protein recognition.
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Affiliation(s)
- Wei Zhang
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
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41
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Abstract
The primary hurdle to improved survival of advanced prostate cancer is our failure to prevent or treat the tumor's progression to its lethal and untreatable stage of androgen independence. Novel treatment modalities designed to prevent androgen-independent progression including prostate cancer metastasis are required. Accelerated identification and characterization of cancer-relevant molecular targets has sparked considerable interest in the development of new generations of anticancer agents that specifically inhibit a progression-relevant target. Antisense oligonucleotides, short synthetic stretches of chemically modified DNA capable of specifically hybridizing to the mRNA of a chosen cancer-relevant target gene, promise to show enhanced specificity for malignant cells with a favorable side-effect profile due to well-defined and tailored modes of action. Although not all of the challenges have been met to date, emerging clinical evidence supports the premise that antisense oligonucleotides stand a realistic chance of emerging as major partners of rationally designed anticancer regimens. The rationale and status of antisense targeting of the treatment resistance factor clusterin and of insulin-like growth factor binding protein (IGFBP) 2 and 5 are discussed.
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Affiliation(s)
- Martin Gleave
- The Prostate Centre at Vancouver General Hospital, Division of Urology, University of British Columbia, Vancouver, BC, Canada, V6H 3Z3.
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42
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Abstract
BACKGROUND AND OBJECTIVES C/EBP homologous protein (CHOP) is an endoplasmic reticulum (ER) stress inducible transcription factor involved in the development of apoptosis, growth arrest, and differentiation. CHOP deficient (chop - / - ) mouse embryonic fibroblasts (MEFs) exposed to ER stresses such as tunicamycin exhibit decreased apoptosis and reduced toxicity when compared to chop + / + control cells. Overexpression of the 70 kDa heat shock stress protein (HSP-70) can inhibit apoptotic pathways. The biological significance of photodynamic therapy (PDT) protocols that induce cellular damage resulting in differential CHOP and stress protein expression patterns was examined. STUDY DESIGN/MATERIALS AND METHODS Wild type mouse radiation induced fibrosarcoma (RIF) cells as well as MEFs with chop + / + and chop - / - genotypes were used with either a mitochondrial and ER localizing porphyrin (PH) photosensitizer or a lysosomal localizing chlorin (NPe6) photosensitizer. PDT induced cytotoxicity, apoptosis, and stress protein expression patterns were determined as a function of cell type and photosensitizer. RESULTS PH mediated PDT induced expression of CHOP and 78 kDa glucose regulated protein (GRP-78), but not HSP-70 while NPe6 mediated PDT induced protein expression of HSP-70 but did not activate CHOP or GRP-78 expression. Enhanced apoptosis and toxicity were observed in chop + / + cells following exposure to tunicamycin or PH mediated PDT when compared to identical treatments in chop - / - cells. NPe6 mediated PDT induced minimally detectable apoptosis in both chop + / + and chop - / - cells and only a modest increase in survival for chop - / - cells. CONCLUSIONS These results demonstrate that PDT activation of CHOP, GRP-78, and HSP-70 varied as a function of photosensitizer subcellular localization and that a single oxidative stress response was not observed following PDT. We also show that CHOP expression increased apoptosis following PH mediated PDT and that increased CHOP expression is associated with enhanced PDT photosensitization.
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Affiliation(s)
- Sam Wong
- Division of Hematology-Oncology, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, California 90027, USA
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Sengupta J, Dhawan L, Lalitkumar PGL, Ghosh D. A multiparametric study of the action of mifepristone used in emergency contraception using the Rhesus monkey as a primate model. Contraception 2003; 68:453-69. [PMID: 14698076 DOI: 10.1016/s0010-7824(03)00108-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mifepristone is a potent agent used in emergency contraception (EC). In the present study, we examined the contraceptive efficacy of mifepristone used in EC and then, using the model of mifepristone-based EC, we investigated its mechanism of action in the rhesus monkey. Sexually mature females were allowed to cohabitate with male animals from 1600 to 900 h of any one day of days 8-17 of cycle without (Group I; n = 6) and with a single dose of mifepristone (Group II, n = 31, 25 mg per animal, subcutaneous) 72 h postcoitus. Blood samples from all animals of Groups I and II were used to determine the concentrations of estradiol (E), progesterone (P) and chorionic gonadotrophin in peripheral circulation for retrospective analysis of the days of ovulation and blastocyst implantation. Four out of six animals (66.6%) in Group I became pregnant, while all 31 monkeys in Group II failed to establish pregnancy along with marginal changes in serum concentrations of E and P. In the second part of the study, animals were subjected to the same experimental protocol followed by collection of endometrial tissue samples on cycle day 22 from animals of both Group I (n = 6) and Group II (n = 24). Endometrial samples were subjected to morphological analysis including mitotic index, immunohistochemistry for vascular endothelial growth factor (VEGF), leukemia inhibitory factor (LIF), transforming growth factor beta1, estradiol receptor (ER), progesterone receptor (PR), proliferating cell nuclear antigen, placental protein 14 (PP 14) and detection of apoptosis by terminal nick end labeling method followed by histometric analysis. The results were retrospectively analyzed between the two groups on the basis of the day of treatment after ovulation: early luteal phase (days 0-3 postovulation) and mid-luteal phase (days 4-7 after ovulation). Mifepristone used in EC in the present study resulted in general loss of functional integrity of epithelial compartment characterized by loss of secretory maturation, increased apoptosis and higher degree of degeneration along with decreased expression of VEGF, LIF, PP14 and ER, while PR level increased as compared to control samples. The vascular compartment appeared to be compromised along with affected morphological features and decreased expression of VEGF, LIF, ER and PR following the administration of mifepristone. It appears that mifepristone used in EC alters the physiological homeostasis in epithelial and vascular compartments of implantation stage endometrium rendering it hostile to blastocyst implantation. Furthermore, the degree to which the endometrial function is affected largely depends on the day of mifepristone treatment in a parameter-specific manner resulting in a higher degree of degenerative changes in samples obtained from animals who received mifepristone during mid-luteal phase of cycles.
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Affiliation(s)
- Jayasree Sengupta
- Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India
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44
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Abstract
Prostate cancers are hormone-dependent malignancies that respond to drugs that reduce circulating testosterone levels or prevent binding of this ligand to the androgen receptor (AR). While effective, these approaches are not curative and, in almost all cases, progression to a castration-resistant state is eventually observed. The mechanisms underlying the development of hormone resistance are poorly defined but several molecular changes are commonly associated with this process. Since a common element of these resistance mechanisms is restoration of AR signaling, agents that target AR expression represent an attractive treatment option for prostate cancer patients with disease progression following castration. Prior to ligand binding, AR exists in a complex with heat shock protein 90 (Hsp90) and other co-chaperones. The AR-Hsp90 interaction maintains AR in a high-affinity ligand-binding conformation, which is necessary for efficient response to hormone. 17-Allyamino-17-demethoxygeldanamycin (17-AAG) is an inhibitor of the Hsp90 chaperone protein. Inhibition of Hsp90 function causes the proteasomal degradation of proteins that require this chaperone for maturation or stability. Hsp90 clients include several proteins of potential importance in mediating prostate cancer progression, including wild-type and mutated AR, HER2, and Akt. In murine models of prostate cancer, 17-AAG causes the degradation of these client proteins at nontoxic doses and inhibits the growth of hormone-naive and castration-resistant tumors. These data suggest that inhibitors of Hsp90 may represent a novel strategy for the treatment of patients with prostate cancer and clinical trials to test this hypothesis are currently ongoing.
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Affiliation(s)
- David B Solit
- Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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45
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Abstract
Radicicol, a macrocyclic antibiotic produced by fungi, was originally isolated many years ago, and was described as tyrosine kinase inhibitor. We also rediscovered radicicol as an inhibitor of signal transduction of oncogene products, such as K-ras and v-Src, using yeast and mammalian cell-based assays. In a study of mechanisms of action, it was revealed that radicicol depletes the Hsp90 client signaling molecules in cells, and thus inhibit the signal transduction pathway. In addition, direct binding of radicicol to the N-terminal ATP/ADP binding site of Hsp90 was shown, and thus radicicol has been recognized as a structurally unique antibiotic that binds and inhibits the molecular chaperone Hsp90. Although radicicol itself has little or no activity in animals because of instability in animals, its oxime derivatives showed potent antitumor activities against human tumor xenograft models. Hsp90 client proteins were depleted and apoptosis was induced in the tumor specimen treated with radicicol oxime derivatives. Taken together, these results suggest that the antitumor activity of radicicol oxime derivatives is mediated by binding to Hsp90 and destabilization of Hsp90 client proteins in the tumor. Among Hsp90 clients, we focused on ErbB2 and Bcr-Abl as examples of important targets of Hsp90 inhibitors. Radicicol oxime showed potent antitumor activity against ER negative/ErbB2 overexpressing breast cancer and Bcr-Abl expressing CML. Putative mechanisms of action and future directions of radicicol oxime against these kinds of tumor are discussed.
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Affiliation(s)
- Shiro Soga
- Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka-ken 411-8731, Japan
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Yan H, Harding JJ, Hui YN, Li MY. Decreased chaperone activity of alpha-crystallin in selenite cataract may result from selenite-induced aggregation. Eye (Lond) 2003; 17:637-45. [PMID: 12855974 DOI: 10.1038/sj.eye.6700419] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To investigate the role of chaperone activity of alpha-crystallin in selenite-induced cataract formation. METHODS Selenite cataract was induced in Sprague-Dawley rats by five subcutaneous injections of sodium selenite over a 20-day period starting at 8-10 days postpartum. alpha-Crystallin was separated from the rat lenses by size-exclusion chromatography. Bovine alpha(L)-crystallin and beta(L)-crystallin were isolated for studies in vitro, and for the chaperone assays. The protective effects of both alpha(H)- and alpha(L)-crystallin were measured spectrophotometrically in four different assay procedures including the thermally induced aggregation of catalase and beta(L)-crystallin, and the fructation- and heat-induced inactivation of catalase. The bovine alpha(L)-crystallin was incubated with different concentrations of sodium selenite for 72 h and then its chaperone activity against heat-induced beta(L)-crystallin aggregation was assayed. The aggregation of selenite-treated alpha(L)-crystallin was analysed by molecular sieve high-performance liquid chromatography (HPLC). RESULTS The protection of alpha(H)-crystallin was less than that of alpha(L)-crystallin in both normal and cataractous lenses. The chaperone activities of both alpha(H)- and alpha(L)-crystallin in selenite cataract were decreased compared with normal lenses. The protection provided by both alpha(H)-crystallin and alpha(L)-crystallin against the thermal aggregation of catalase was much greater than their protection against thermally and chemically induced inactivation. HPLC analysis demonstrated aggregation of alpha-crystallin by sodium selenite after 24 h incubation in a dose-dependent fashion. CONCLUSION The chaperone activity of alpha-crystallin presented parallel patterns of activity with different methods, further supporting the view that the different assays measure essentially the same property. The decreased chaperone activity of alpha-crystallin in selenite cataract may result from selenite-induced aggregation.
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Affiliation(s)
- H Yan
- Department of Ophthalmology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
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Steffan JS, Thompson LM. Targeting aggregation in the development of therapeutics for the treatment of Huntington's disease and other polyglutamine repeat diseases. Expert Opin Ther Targets 2003; 7:201-13. [PMID: 12667098 DOI: 10.1517/14728222.7.2.201] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Huntington's disease (HD) is one of a number of familial polyglutamine (polyQ) repeat diseases. These neurodegenerative disorders are caused by expression of otherwise unrelated proteins that contain an expansion of a polyQ tract, rendering them toxic to specific subsets of vulnerable neurons. These expanded repeats have an inherent propensity to aggregate; insoluble neuronal nuclear and cytoplasmic polyQ aggregates or inclusions are hallmarks of the disorders [1,2]. In HD, inclusions in diseased brains often precede onset of symptoms, and have been proposed to be involved in pathogenicity [3-5]. Various strategies to block the process of aggregation have been developed in an effort to create drugs that decrease neurotoxicity. A discussion of the effect of antibodies, caspase inhibitors, chemical inhibitors, heat-shock proteins, suppressor peptides and transglutaminase inhibitors upon aggregation and disease is presented.
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Affiliation(s)
- Joan S Steffan
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-4260, USA.
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Stephens AC, Rivers RPA. Antisense oligonucleotide therapy in cancer. Curr Opin Mol Ther 2003; 5:118-22. [PMID: 12772500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The sequencing of the human genome has highlighted some of the genes that are of importance in disease states. This has provided opportunities for the development of new therapeutics to target a wide range of human diseases. These new drugs are intended to be highly specific; antisense oligonucleotides (ONs) are one such class of new drugs. ONs are short pieces of DNA which hybridize to a specific target mRNA blocking its translation to protein, thereby inhibiting the action of the gene. Several genes known to be of importance in the regulation of apoptosis, cell growth, metastasis and angiogenesis provide a tantalizing prospect for the development of anticancer agents. The phosphorothioate antisense ONs are the current choice for antisense therapy. This article reviews the current strategies for antisense targets in cancer therapy.
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Affiliation(s)
- Alick C Stephens
- Academic Department of Paediatrics, Imperial College London, St Mary's Campus, Norfolk Place, Paddington, London, W2 1PG, UK.
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Winge I, Pryme IF. Sodium butyrate stimulates the synthesis of firefly luciferase in transfected CHO cells but levels of BiP chaperone are unaffected. Cell Biol Int 2003; 26:489-94. [PMID: 12119175 DOI: 10.1006/cbir.2002.0881] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A stably transfected CHO cell line (LUCLEAD) was used where the coding region of native Firefly luciferase was linked to the 3'-UTR of the bovine growth hormone, and the 5'-nucleotides coding for the albumin signal peptide were linked to the N-terminal end of the luciferase coding region. Incubation of cells with 1 or 2 mM sodium butyrate (SB) for 72 h had no effect on cell growth since cultures reached confluency at the same time as control cells. Although cell cultures incubated with SB at a concentration of 4 mM were only about 60% confluent the luciferase content was about 5-fold higher than that in control cells. Cells incubated with either 1 or 2 mM SB showed intermediate levels of luciferase content. The amount of the chaperone BiP in the cells was not affected by incubation with SB. The results indicate that SB can be used to effectively promote synthesis of recombinant luciferase.
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Affiliation(s)
- Ingeborg Winge
- Department of Biochemistry and Molecular Biology, University of Bergen, Arstadveien 19, NO-5009 Bergen, Norway
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