1
|
Xu L, Liu R, Fang J, Zhang N, Pu F, Lei Z, Ding W, Jiang Y. Cytotoxic and Antifungal Staurosporine Derivatives from Marine-Derived Actinomycete Streptomyces sp. ZS-A121. Chem Biodivers 2024; 21:e202301712. [PMID: 38031386 DOI: 10.1002/cbdv.202301712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/29/2023] [Accepted: 11/29/2023] [Indexed: 12/01/2023]
Abstract
A novel staurosporine derivate, streptomholyrine A (1), along with 6 known compounds were identified from the rice-based solid fermentation of marine-derived Streptomyces sp. ZS-A121. The planar structure and absolute configuration of streptomholyrine A were elucidated using a combination of 1D, 2D NMR, HRESIMS data analysis, chemical transformation, ECD and NMR calculations. Screening of all these compounds revealed their cytotoxic activity against HCT-116 cell lines, with IC50 values ranging from 0.012 to 11.67 μM, except for the known 1H-indole-3-hydroxyacetyl, which showed no inhibition activity. Furthermore, streptomholyrine A, along with two known staurosporine derivatives, k252d and staurosporine, exhibited activities against Candida albicans, with MICs of 12.5, 25.0 and 50.0 μg/ml, respectively.
Collapse
Affiliation(s)
- Lei Xu
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316021, People's Republic of China
| | - Renshuang Liu
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316021, People's Republic of China
| | - Jiebin Fang
- Ocean College, Zhejiang University, Zhoushan, 316021, People's Republic of China
| | - Ningjing Zhang
- Ocean College, Zhejiang University, Zhoushan, 316021, People's Republic of China
| | - Fanqi Pu
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316021, People's Republic of China
| | - Zhen Lei
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316021, People's Republic of China
| | - Wanjing Ding
- Ocean College, Zhejiang University, Zhoushan, 316021, People's Republic of China
| | - Yongjun Jiang
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, 316021, People's Republic of China
| |
Collapse
|
2
|
Akrami H, Shamsdin SA, Nikmanesh Y, Fattahi M. Effect of Mir-4270 Inhibitor and Mimic on Viability and Stemness in Gastric Cancer Stem-Like Cells Derived from MKN-45 Cell Line. Iran Biomed J 2023; 27:100-7. [PMID: 37070617 PMCID: PMC10314761 DOI: 10.61186/ibj.3851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/18/2022] [Indexed: 12/17/2023]
Abstract
Background MicroRNAs (miRNAs) are significant regulatory factors in stem cell proliferation, and change in miRNA expression influences the cancer stem cell viability and gene expression. Herein, we evaluated the effect of the hsa-miR-4270 inhibitor and its mimic on the expression of stem cell markers in gastric cancer (GC) stem-like cells. Methods GC stem-like cells were isolated from the MKN-45 cell line by a non-adherent surface system. The cells were confirmed by differentiation assays using dexamethasone and insulin as adipogenesis-inducing agents and also Staurosporine as a neural-inducing agent. Isolated GC stem-like cells were treated with different concentrations (0, 15, 20, 25, 30, 40, 50, and 60 nM) of hsa-miR-4270 inhibitor and its mimic. The quantity of cell viability was determined by trypan blue method. Transcription of the stem cell marker genes, including CD44, OCT3/4, SOX2, Nanog, and KLF4, was evaluated by real-time RT-PCR. Results The results showed that GC stem-like cells were differentiated into both adipose cells using dexamethasone and insulin and neural cells by Staurosporine. Treatment of GC stem-like cells with hsa-miR-4270 inhibitor decreased cell viability and downregulated OCT3/4, CD44, and Nanog to 86%, 79%, and 91% respectively. Also, SOX2 and KLF4 were overexpressed to 8.1- and 1.94-folds, respectively. However, hsa-miR-4270 mimic had opposite effects on the cell viability and gene expression of the stem cell markers. Conclusion The effect of hsa-miR-4270 inhibitor and its mimic on the expression of the stem cell markers in GCSCs indicated that hsa-miR-4270 stimulates the stemness property of GCSCs, likely through stimulating the development of gastric stem cells.
Collapse
Affiliation(s)
- Hassan Akrami
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | | | | |
Collapse
|
3
|
Akrami H, Shamsdin SA, Nikmanesh Y, Fattahi M. Effect of Mir-4270 Inhibitor and Mimic on Viability and Stemness in Gastric Cancer Stem-Like Cells Derived from MKN-45 Cell Line. Iran Biomed J 2023; 27:100-7. [PMID: 37070617 DOI: 10.52547/ibj.3851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Background MicroRNAs (miRNAs) are significant regulatory factors in stem cell proliferation, and change in miRNA expression influences the cancer stem cell viability and gene expression. Herein, we evaluated the effect of the hsa-miR-4270 inhibitor and its mimic on the expression of stem cell markers in gastric cancer (GC) stem-like cells. Methods GC stem-like cells were isolated from the MKN-45 cell line by a non-adherent surface system. The cells were confirmed by differentiation assays using dexamethasone and insulin as adipogenesis-inducing agents and also Staurosporine as a neural-inducing agent. Isolated GC stem-like cells were treated with different concentrations (0, 15, 20, 25, 30, 40, 50, and 60 nM) of hsa-miR-4270 inhibitor and its mimic. The quantity of cell viability was determined by trypan blue method. Transcription of the stem cell marker genes, including CD44, OCT3/4, SOX2, Nanog, and KLF4, was evaluated by real-time RT-PCR. Results The results showed that GC stem-like cells were differentiated into both adipose cells using dexamethasone and insulin and neural cells by Staurosporine. Treatment of GC stem-like cells with hsa-miR-4270 inhibitor decreased cell viability and downregulated OCT3/4, CD44, and Nanog to 86%, 79%, and 91% respectively. Also, SOX2 and KLF4 were overexpressed to 8.1- and 1.94-folds, respectively. However, hsa-miR-4270 mimic had opposite effects on the cell viability and gene expression of the stem cell markers. Conclusion The effect of hsa-miR-4270 inhibitor and its mimic on the expression of the stem cell markers in GCSCs indicated that hsa-miR-4270 stimulates the stemness property of GCSCs, likely through stimulating the development of gastric stem cells.
Collapse
Affiliation(s)
- Hassan Akrami
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyedeh Azra Shamsdin
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Yousef Nikmanesh
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammadreza Fattahi
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
4
|
Rietscher K, Jahnke HG, Rübsam M, Lin EW, Has C, Omary MB, Niessen CM, Magin TM. Kinase Inhibition by PKC412 Prevents Epithelial Sheet Damage in Autosomal Dominant Epidermolysis Bullosa Simplex through Keratin and Cell Contact Stabilization. J Invest Dermatol 2022; 142:3282-3293. [PMID: 35691363 DOI: 10.1016/j.jid.2022.05.1088] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 04/24/2022] [Accepted: 05/22/2022] [Indexed: 01/05/2023]
Abstract
Epidermolysis bullosa simplex (EBS) is a severe and potentially life-threatening disorder for which no adequate therapy exists. Most cases are caused by dominant sequence variations in keratin genes K5 or K14, leading to the formation of cytoplasmic keratin aggregates, profound keratinocyte fragility, and cytolysis. We hypothesized that pharmacological reduction of keratin aggregates, which compromise keratinocyte integrity, represents a viable strategy for the treatment of EBS. In this study, we show that the multikinase inhibitor PKC412, which is currently in clinical use for acute myeloid leukemia and advanced systemic mastocytosis, reduced keratin aggregation by 40% in patient-derived K14.R125C EBS-associated keratinocytes. Using a combination of epithelial shear stress assay and real-time impedance spectroscopy, we show that PKC412 restored intercellular adhesion. Molecularly, global phosphoproteomic analysis together with immunoblots using phosphoepitope-specific antibodies revealed that PKC412 treatment altered phosphorylated sites on keratins and desmoplakin. Thus, our data provide a proof of concept to repurpose existing drugs for the targeted treatment of EBS and showcase how one broad-range kinase inhibitor reduced keratin filament aggregation in patient-derived EBS keratinocytes and the fragility of EBS cell monolayers. Our study paves the way for a clinical trial using PKC412 for systemic or local application in patients with EBS.
Collapse
Affiliation(s)
- Katrin Rietscher
- Institute of Biology, Division of Cell and Developmental Biology, Leipzig University, Leipzig, Germany.
| | - Heinz-Georg Jahnke
- Division of Molecular Biological-Biochemical Processing Technology, Center for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | - Matthias Rübsam
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department Cell Biology of the Skin, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Eric W Lin
- Division of Gastroenterology and Hepatology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Cristina Has
- Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany
| | - M Bishr Omary
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey, USA; Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey, USA
| | - Carien M Niessen
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department Cell Biology of the Skin, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Thomas M Magin
- Institute of Biology, Division of Cell and Developmental Biology, Leipzig University, Leipzig, Germany
| |
Collapse
|
5
|
Alshamleh I, Krause N, Richter C, Kurrle N, Serve H, Günther UL, Schwalbe H. Real-Time NMR Spectroscopy for Studying Metabolism. Angew Chem Int Ed Engl 2020; 59:2304-2308. [PMID: 31730253 PMCID: PMC7004128 DOI: 10.1002/anie.201912919] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/12/2019] [Indexed: 12/19/2022]
Abstract
Current metabolomics approaches utilize cellular metabolite extracts, are destructive, and require high cell numbers. We introduce here an approach that enables the monitoring of cellular metabolism at lower cell numbers by observing the consumption/production of different metabolites over several kinetic data points of up to 48 hours. Our approach does not influence cellular viability, as we optimized the cellular matrix in comparison to other materials used in a variety of in-cell NMR spectroscopy experiments. We are able to monitor real-time metabolism of primary patient cells, which are extremely sensitive to external stress. Measurements are set up in an interleaved manner with short acquisition times (approximately 7 minutes per sample), which allows the monitoring of up to 15 patient samples simultaneously. Further, we implemented our approach for performing tracer-based assays. Our approach will be important not only in the metabolomics fields, but also in individualized diagnostics.
Collapse
Affiliation(s)
- Islam Alshamleh
- Institute of Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-University FrankfurtMax-von-Laue Str. 760438FrankfurtGermany
| | - Nina Krause
- Institute of Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-University FrankfurtMax-von-Laue Str. 760438FrankfurtGermany
| | - Christian Richter
- Institute of Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-University FrankfurtMax-von-Laue Str. 760438FrankfurtGermany
| | - Nina Kurrle
- German Cancer Consortium (DKTK) and DKFZ69120HeidelbergGermany
- Department of Medicine 2, Hematology/OncologyGoethe University60590Frankfurt am MainGermany
- Frankfurt Cancer Institute (FCI)60590Frankfurt am MainGermany
| | - Hubert Serve
- German Cancer Consortium (DKTK) and DKFZ69120HeidelbergGermany
- Department of Medicine 2, Hematology/OncologyGoethe University60590Frankfurt am MainGermany
- Frankfurt Cancer Institute (FCI)60590Frankfurt am MainGermany
| | - Ulrich L. Günther
- Institute of Chemistry and MetabolomicsUniversity of LuebeckRatzeburger Allee 16023562LuebeckGermany
| | - Harald Schwalbe
- Institute of Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe-University FrankfurtMax-von-Laue Str. 760438FrankfurtGermany
| |
Collapse
|
6
|
Childs D, Bach K, Franken H, Anders S, Kurzawa N, Bantscheff M, Savitski MM, Huber W. Nonparametric Analysis of Thermal Proteome Profiles Reveals Novel Drug-binding Proteins. Mol Cell Proteomics 2019; 18:2506-2515. [PMID: 31582558 PMCID: PMC6885700 DOI: 10.1074/mcp.tir119.001481] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 09/01/2019] [Indexed: 12/19/2022] Open
Abstract
Detecting the targets of drugs and other molecules in intact cellular contexts is a major objective in drug discovery and in biology more broadly. Thermal proteome profiling (TPP) pursues this aim at proteome-wide scale by inferring target engagement from its effects on temperature-dependent protein denaturation. However, a key challenge of TPP is the statistical analysis of the measured melting curves with controlled false discovery rates at high proteome coverage and detection power. We present nonparametric analysis of response curves (NPARC), a statistical method for TPP based on functional data analysis and nonlinear regression. We evaluate NPARC on five independent TPP data sets and observe that it is able to detect subtle changes in any region of the melting curves, reliably detects the known targets, and outperforms a melting point-centric, single-parameter fitting approach in terms of specificity and sensitivity. NPARC can be combined with established analysis of variance (ANOVA) statistics and enables flexible, factorial experimental designs and replication levels. An open source software implementation of NPARC is provided.
Collapse
Affiliation(s)
- Dorothee Childs
- European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstraβe 1, 69117 Heidelberg, Germany; Cellzome GmbH, GlaxoSmithKline, Meyerhofstraβe 1, 69117 Heidelberg, Germany
| | - Karsten Bach
- Department of Pharmacology, University of Cambridge, CB2 1PD, Cambridge, UK; Cancer Research UK Cambridge Cancer Centre, CB2 0RE, Cambridge, UK
| | - Holger Franken
- Cellzome GmbH, GlaxoSmithKline, Meyerhofstraβe 1, 69117 Heidelberg, Germany
| | - Simon Anders
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Nils Kurzawa
- European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstraβe 1, 69117 Heidelberg, Germany
| | - Marcus Bantscheff
- Cellzome GmbH, GlaxoSmithKline, Meyerhofstraβe 1, 69117 Heidelberg, Germany
| | - Mikhail M Savitski
- European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstraβe 1, 69117 Heidelberg, Germany
| | - Wolfgang Huber
- European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstraβe 1, 69117 Heidelberg, Germany.
| |
Collapse
|
7
|
Schlafer D. Management of Midostaurin-CYP3A4 Drug-Drug Interactions in Patients With Acute Myeloid Leukemia. Oncology (Williston Park) 2019; 33:629381. [PMID: 31365750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
|
8
|
Dawes BE, Gao J, Atkins C, Nelson JT, Johnson K, Wu P, Freiberg AN. Human neural stem cell-derived neuron/astrocyte co-cultures respond to La Crosse virus infection with proinflammatory cytokines and chemokines. J Neuroinflammation 2018; 15:315. [PMID: 30442185 PMCID: PMC6236894 DOI: 10.1186/s12974-018-1356-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 10/31/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND La Crosse virus (LACV) causes pediatric encephalitis in the USA. LACV induces severe inflammation in the central nervous system, but the recruitment of inflammatory cells is poorly understood. A deeper understanding of LACV-induced neural pathology is needed in order to develop treatment options. However, there is a severe limitation of relevant human neuronal cell models of LACV infection. METHODS We utilized human neural stem cell (hNSC)-derived neuron/astrocyte co-cultures to study LACV infection in disease-relevant primary cells. hNSCs were differentiated into neurons and astrocytes and infected with LACV. To characterize susceptibility and responses to infection, we measured viral titers and levels of viral RNA, performed immunofluorescence analysis to determine the cell types infected, performed apoptosis and cytotoxicity assays, and evaluated cellular responses to infection using qRT-PCR and Bioplex assays. RESULTS hNSC-derived neuron/astrocyte co-cultures were susceptible to LACV infection and displayed apoptotic responses as reported in previous in vitro and in vivo studies. Neurons and astrocytes are both targets of LACV infection, with neurons becoming the predominant target later in infection possibly due to astrocytic responses to IFN. Additionally, neuron/astrocyte co-cultures responded to LACV infection with strong proinflammatory cytokine, chemokine, as well as MMP-2, MMP-7, and TIMP-1 responses. CONCLUSIONS hNSC-derived neuron/astrocyte co-cultures reproduce key aspects of LACV infection in humans and mice and are useful models to study encephalitic viruses. Specifically, we show astrocytes to be susceptible to LACV infection and that neurons and astrocytes are important drivers of the inflammatory responses seen in LACV infection through the production of proinflammatory cytokines and chemokines.
Collapse
Affiliation(s)
- Brian E. Dawes
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, USA
| | - Junling Gao
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, USA
| | - Colm Atkins
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
| | - Jacob T. Nelson
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
| | - Kendra Johnson
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, USA
| | - Ping Wu
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, USA
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, USA
| |
Collapse
|
9
|
Alexeeva M, Åberg E, Engh RA, Rothweiler U. The structure of a dual-specificity tyrosine phosphorylation-regulated kinase 1A-PKC412 complex reveals disulfide-bridge formation with the anomalous catalytic loop HRD(HCD) cysteine. Acta Crystallogr D Biol Crystallogr 2015; 71:1207-15. [PMID: 25945585 DOI: 10.1107/s1399004715005106] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/12/2015] [Indexed: 01/12/2023]
Abstract
Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is a protein kinase associated with neuronal development and brain physiology. The DYRK kinases are very unusual with respect to the sequence of the catalytic loop, in which the otherwise highly conserved arginine of the HRD motif is replaced by a cysteine. This replacement, along with the proximity of a potential disulfide-bridge partner from the activation segment, implies a potential for redox control of DYRK family activities. Here, the crystal structure of DYRK1A bound to PKC412 is reported, showing the formation of the disulfide bridge and associated conformational changes of the activation loop. The DYRK kinases represent emerging drug targets for several neurological diseases as well as cancer. The observation of distinct activation states may impact strategies for drug targeting. In addition, the characterization of PKC412 binding offers new insights for DYRK inhibitor discovery.
Collapse
Affiliation(s)
- Marina Alexeeva
- Department of Chemistry, The Norwegian Structural Biology Centre, The Arctic University of Norway, 9037 Tromsø, Norway
| | - Espen Åberg
- Department of Chemistry, The Norwegian Structural Biology Centre, The Arctic University of Norway, 9037 Tromsø, Norway
| | - Richard A Engh
- Department of Chemistry, The Norwegian Structural Biology Centre, The Arctic University of Norway, 9037 Tromsø, Norway
| | - Ulli Rothweiler
- Department of Chemistry, The Norwegian Structural Biology Centre, The Arctic University of Norway, 9037 Tromsø, Norway
| |
Collapse
|
10
|
Nakamura-Lopez Y, Villegas-Sepúlveda N, Gómez B. RSV P-protein impairs extrinsic apoptosis pathway in a macrophage-like cell line persistently infected with respiratory syncytial virus. Virus Res 2015; 204:82-7. [PMID: 25937519 DOI: 10.1016/j.virusres.2015.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [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: 02/10/2015] [Revised: 04/22/2015] [Accepted: 04/23/2015] [Indexed: 01/12/2023]
Abstract
Disabling apoptosis is practically a mandatory step for establishing and maintaining viral persistence in host cells. Thus, persisting viruses have evolved strategies to impair apoptosis mechanisms. Apoptosis can be induced through either the intrinsic or the extrinsic pathway. Previously, we reported that staurosporine-induced intrinsic apoptotic pathway was down-regulated in a macrophage cell line persistently infected with respiratory syncytial virus (RSV, MΦP). In the present study, our results showed that the extrinsic apoptotic pathway was also impaired in this cell line and that RSV P-protein interfered with the onset of the extrinsic apoptotic process. In this work, we analyzed and compared the expression of several components of the DISC complex (i.e., TNF-α, TNFR1, caspase-8, and cIAP2) in MΦP cells with that in mock-infected macrophages. Additionally, by using DNA sequence analysis in silico, we searched for an RSV protein putatively interfering with the triggering of the extrinsic apoptotic process. The analysis showed that viral P-protein shared a 52% homology with the caspase-8 death domain. Subsequently, the nucleic acid sequence of the viral P-protein was cloned and transfected into the macrophage cell line; the effect of this transfection on staurosporine-induced apoptosis was evaluated by assaying for cell viability and caspases-8 and -9 activity. The results revealed that although caspase-9 was activated, the activity of the caspase-8 was impaired in the RSV P-protein transfected cells; more of these cells survived than did mock-transfected cells. These findings suggest that P-protein impaired the extrinsic pathway of apoptosis. Our findings contribute to the understanding of the mechanism by which viral proteins subvert the extrinsic apoptosis process in cells persistently infected with RSV.
Collapse
Affiliation(s)
- Yuko Nakamura-Lopez
- Laboratory of Virology, Department of Microbiology and Parasitology, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Ciudad Universitaria, México, D.F. 04360, Mexico.
| | - Nicolas Villegas-Sepúlveda
- Department of Molecular Biomedicine, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, México, D.F. 07360, Mexico.
| | - Beatriz Gómez
- Laboratory of Virology, Department of Microbiology and Parasitology, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Ciudad Universitaria, México, D.F. 04360, Mexico.
| |
Collapse
|
11
|
Murmann T, Carrillo-García C, Veit N, Courts C, Glassmann A, Janzen V, Madea B, Reinartz M, Harzen A, Nowak M, Perner S, Winter J, Probstmeier R. Staurosporine and extracellular matrix proteins mediate the conversion of small cell lung carcinoma cells into a neuron-like phenotype. PLoS One 2014; 9:e86910. [PMID: 24586258 PMCID: PMC3938400 DOI: 10.1371/journal.pone.0086910] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 12/17/2013] [Indexed: 11/23/2022] Open
Abstract
Small cell lung carcinomas (SCLCs) represent highly aggressive tumors with an overall five-year survival rate in the range of 5 to 10%. Here, we show that four out of five SCLC cell lines reversibly develop a neuron-like phenotype on extracellular matrix constituents such as fibronectin, laminin or thrombospondin upon staurosporine treatment in an RGD/integrin-mediated manner. Neurite-like processes extend rapidly with an average speed of 10 µm per hour. Depending on the cell line, staurosporine treatment affects either cell cycle arrest in G2/M phase or induction of polyploidy. Neuron-like conversion, although not accompanied by alterations in the expression pattern of a panel of neuroendocrine genes, leads to changes in protein expression as determined by two-dimensional gel electrophoresis. It is likely that SCLC cells already harbour the complete molecular repertoire to convert into a neuron-like phenotype. More extensive studies are needed to evaluate whether the conversion potential of SCLC cells is suitable for therapeutic interventions.
Collapse
Affiliation(s)
- Tamara Murmann
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital of Bonn, Bonn, Germany
| | | | - Nadine Veit
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital of Bonn, Bonn, Germany
| | | | | | - Viktor Janzen
- Department of Hematology and Oncology, University Hospital of Bonn, Bonn, Germany
| | - Burkhard Madea
- Institute of Legal Medicine, University of Bonn, Bonn, Germany
| | - Markus Reinartz
- Oral Cell Biology Group, Department of Periodontology, Operative and Preventive Dentistry, Bonn, Germany
| | - Anne Harzen
- Proteomics Group, Max-Planck-Institute for Plant Breeding Research, Cologne, Germany
| | - Michael Nowak
- Department of Prostate Cancer Research, Institute of Pathology, University Hospital of Bonn, Bonn, Germany
| | - Sven Perner
- Department of Prostate Cancer Research, Institute of Pathology, University Hospital of Bonn, Bonn, Germany
| | - Jochen Winter
- Oral Cell Biology Group, Department of Periodontology, Operative and Preventive Dentistry, Bonn, Germany
| | - Rainer Probstmeier
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital of Bonn, Bonn, Germany
- * E-mail:
| |
Collapse
|
12
|
Abstract
We report that an HSV-2 UL14 protein expressing cell line (14/HEp-2) was more resistant to apoptosis induced by osmotic shock and certain drugs than its parental cell line. Furthermore, HSV-1 UL14 protein deletion virus (UL14D) showed weaker inhibition of apoptosis compared to the rescued virus UL14R. The protein's anti-apoptotic function may derive from its heat shock protein-like properties.
Collapse
Affiliation(s)
- Yohei Yamauchi
- Laboratory of Virology, Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Nagoya, Aichi 466-8550, Japan
| | | | | | | |
Collapse
|
13
|
De Franchi E, Schalon C, Messa M, Onofri F, Benfenati F, Rognan D. Binding of protein kinase inhibitors to synapsin I inferred from pair-wise binding site similarity measurements. PLoS One 2010; 5:e12214. [PMID: 20808948 PMCID: PMC2922380 DOI: 10.1371/journal.pone.0012214] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 07/26/2010] [Indexed: 11/18/2022] Open
Abstract
Predicting off-targets by computational methods is getting increasing importance in early drug discovery stages. We herewith present a computational method based on binding site three-dimensional comparisons, which prompted us to investigate the cross-reaction of protein kinase inhibitors with synapsin I, an ATP-binding protein regulating neurotransmitter release in the synapse. Systematic pair-wise comparison of the staurosporine-binding site of the proto-oncogene Pim-1 kinase with 6,412 druggable protein-ligand binding sites suggested that the ATP-binding site of synapsin I may recognize the pan-kinase inhibitor staurosporine. Biochemical validation of this hypothesis was realized by competition experiments of staurosporine with ATP-gamma(35)S for binding to synapsin I. Staurosporine, as well as three other inhibitors of protein kinases (cdk2, Pim-1 and casein kinase type 2), effectively bound to synapsin I with nanomolar affinities and promoted synapsin-induced F-actin bundling. The selective Pim-1 kinase inhibitor quercetagetin was shown to be the most potent synapsin I binder (IC50 = 0.15 microM), in agreement with the predicted binding site similarities between synapsin I and various protein kinases. Other protein kinase inhibitors (protein kinase A and chk1 inhibitor), kinase inhibitors (diacylglycerolkinase inhibitor) and various other ATP-competitors (DNA topoisomerase II and HSP-90alpha inhibitors) did not bind to synapsin I, as predicted from a lower similarity of their respective ATP-binding sites to that of synapsin I. The present data suggest that the observed downregulation of neurotransmitter release by some but not all protein kinase inhibitors may also be contributed by a direct binding to synapsin I and phosphorylation-independent perturbation of synapsin I function. More generally, the data also demonstrate that cross-reactivity with various targets may be detected by systematic pair-wise similarity measurement of ligand-annotated binding sites.
Collapse
Affiliation(s)
- Enrico De Franchi
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Claire Schalon
- Structural Chemogenomics, Laboratory of Therapeutic Innovation, CNRS UMR 7200, Université de Strasbourg, Illkirch, France
| | - Mirko Messa
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Franco Onofri
- Department of Experimental Medicine, University of Genova and Istituto Nazionale di Neuroscienze, Genova, Italy
| | - Fabio Benfenati
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
- Department of Experimental Medicine, University of Genova and Istituto Nazionale di Neuroscienze, Genova, Italy
| | - Didier Rognan
- Structural Chemogenomics, Laboratory of Therapeutic Innovation, CNRS UMR 7200, Université de Strasbourg, Illkirch, France
- * E-mail:
| |
Collapse
|
14
|
Jäkel A, Clark H, Reid KBM, Sim RB. The human lung surfactant proteins A (SP-A) and D (SP-D) interact with apoptotic target cells by different binding mechanisms. Immunobiology 2009; 215:551-8. [PMID: 19880212 DOI: 10.1016/j.imbio.2009.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [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] [Received: 07/17/2009] [Revised: 09/14/2009] [Accepted: 09/15/2009] [Indexed: 01/21/2023]
Abstract
The role of the lung surfactant proteins SP-A and SP-D in immune defence is well established. They bind to foreign organisms that invade the lungs and target them for phagocytic clearance by resident alveolar macrophages. SP-A and SP-D also bind to various apoptotic cells and facilitate their phagocytic uptake. To date, the molecular mechanisms by which the lung surfactant proteins interact with apoptotic cells and phagocytes are poorly understood. The aims of this study were to investigate further the interactions between SP-A and SP-D and apoptotic cells using human neutrophils and Jurkat cells as model systems. Specifically the binding behaviour of SP-A and SP-D with viable, early apoptotic and late apoptotic cells was investigated and compared. SP-A and SP-D show very distinct binding to the various cell types. SP-A bound to viable and early apoptotic cells in a predominantly Ca(2+)-dependent manner but the interaction with late apoptotic cells was Ca(2+)-independent, suggesting involvement of other than the lectin- or Ca(2+)-binding sites. This was consistent for neutrophils and Jurkat cells. SP-D in contrast, did not interact with viable and early apoptotic Jurkat cells but strongly and in a Ca(2+)-independent manner with late apoptotic Jurkat cells. SP-D-binding to viable and early apoptotic neutrophils was inhibited by maltose and ethylene-diamin-tetra-acetate (EDTA), suggesting lectin-binding site involvement whereas the binding to late apoptotic neutrophils was predominantly Ca(2+)-independent. These results represent a detailed study of the binding behaviour of SP-A and SP-D with different cell types and stages of viability. The mechanisms of these interactions appear to involve preferential recognition of different ligands on the apoptotic cell surface, which may include nucleic acid, phospholipid, protein and glycan structures.
Collapse
Affiliation(s)
- Anne Jäkel
- Department of Biochemistry, University of Oxford, Oxford, UK.
| | | | | | | |
Collapse
|
15
|
Olla S, Manetti F, Crespan E, Maga G, Angelucci A, Schenone S, Bologna M, Botta M. Indolyl-pyrrolone as a new scaffold for Pim1 inhibitors. Bioorg Med Chem Lett 2009; 19:1512-6. [PMID: 19179076 DOI: 10.1016/j.bmcl.2009.01.005] [Citation(s) in RCA: 23] [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] [Received: 10/10/2008] [Revised: 12/22/2008] [Accepted: 01/06/2009] [Indexed: 11/19/2022]
Abstract
Pim1 belongs to a family of serine/threonine kinases, which is involved in the control of cell growth, differentiation, and apoptosis. Pim1 plays a pivotal role in cytokine signaling and is implicated in the development of a large number of tumors, representing a very attractive target for anticancer therapy. In this work, we applied a virtual screening protocol aimed at identifying small molecules able to inhibit Pim1 activity. The search of novel inhibitors was performed through a structure-based molecular modeling approach, taking advantage of the availability of the three-dimensional crystal structure of inhibitors bound to Pim1. Starting from the knowledge of protein-ligand complexes, the software LigandScout was used to generate pharmacophoric models, in turn used as queries to perform a virtual screening of databases, followed by docking experiments. As a result, a restricted set of candidates for biological testing was identified. Finally, among the six compounds selected as potential inhibitors of Pim1, two candidates endowed with a significant activity against Pim1 emerged. Interestingly, one of these compounds has a chemical scaffold different from inhibitors previously identified.
Collapse
Affiliation(s)
- Stefania Olla
- Dipartimento Farmaco Chimico Tecnologico, Università degli Studi di Siena, Via Alcide de Gasperi 2, I-53100 Siena, Italy
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Meng L, Mattoon D, Predki P. Small molecule protein interaction profiling with functional protein microarrays. Methods Mol Biol 2009; 572:177-188. [PMID: 20694692 DOI: 10.1007/978-1-60761-244-5_11] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Small molecules possess the ability to interact with proteins and perturb their specific functions, a property that has been exploited for numerous research applications and to produce therapeutic agents in disease treatment. However, commonly utilized mass spectrometry-based approaches for identifying the target proteins for a small molecule have a number of limitations, particularly in terms of throughput and time and resource consumption. In addition, current technologies lack a mechanism to broadly assess the selectivity profile of the small molecule, which may be important for understanding off-target effects of the compound. Protein microarray technology has emerged as a powerful tool in the systems biology arsenal. Here, we describe how protein microarray technology can be applied to the study of small molecule protein interactions, with sensitivity sufficient to detect interactions with low muM affinity. These assays are highly reproducible, sensitive, and scalable, and provide an enabling technology for small molecule selectivity profiling in the context of drug development.
Collapse
Affiliation(s)
- Lihao Meng
- Life Technologies Corporation, Carlsbad, CA, USA
| | | | | |
Collapse
|
17
|
Verbert L, Lee B, Kocks SL, Assefa Z, Parys JB, Missiaen L, Callewaert G, Fissore RA, De Smedt H, Bultynck G. Caspase-3-truncated type 1 inositol 1,4,5-trisphosphate receptor enhances intracellular Ca2+ leak and disturbs Ca2+ signalling. Biol Cell 2008; 100:39-49. [PMID: 17868032 PMCID: PMC2909191 DOI: 10.1042/bc20070086] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [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: 11/17/2022]
Abstract
BACKGROUND INFORMATION The IP(3)R (inositol 1,4,5-trisphosphate receptor) is a tetrameric channel that accounts for a large part of the intracellular Ca(2+) release in virtually all cell types. We have previously demonstrated that caspase-3-mediated cleavage of IP(3)R1 during cell death generates a C-terminal fragment of 95 kDa comprising the complete channel domain. Expression of this truncated IP(3)R increases the cellular sensitivity to apoptotic stimuli, and it was postulated to be a constitutively active channel. RESULTS In the present study, we demonstrate that expression of the caspase-3-cleaved C-terminus of IP(3)R1 increased the rate of thapsigargin-mediated Ca(2+) leak and decreased the rate of Ca(2+) uptake into the ER (endoplasmic reticulum), although it was not sufficient by itself to deplete intracellular Ca(2+) stores. We detected the truncated IP(3)R1 in different cell types after a challenge with apoptotic stimuli, as well as in aged mouse oocytes. Injection of mRNA corresponding to the truncated IP(3)R1 blocked sperm factor-induced Ca(2+) oscillations and induced an apoptotic phenotype. CONCLUSIONS In the present study, we show that caspase-3-mediated truncation of IP(3)R1 enhanced the Ca(2+) leak from the ER. We suggest a model in which, in normal conditions, the increased Ca(2+) leak is largely compensated by enhanced Ca(2+)-uptake activity, whereas in situations where the cellular metabolism is compromised, as occurring in aging oocytes, the Ca(2+) leak acts as a feed-forward mechanism to divert the cell into apoptosis.
Collapse
Affiliation(s)
- Leen Verbert
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Bora Lee
- Program and Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01002, U.S.A
| | - Sarah L. Kocks
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Zerihun Assefa
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Jan B. Parys
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Ludwig Missiaen
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Geert Callewaert
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Rafael A. Fissore
- Program and Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01002, U.S.A
| | - Humbert De Smedt
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signalling, Division of Physiology, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 bus 802, B-3000 Leuven, Belgium
- To whom correspondence should be addressed ()
| |
Collapse
|
18
|
King MA, Eddaoudi A, Davies DC. A comparison of three flow cytometry methods for evaluating mitochondrial damage during staurosporine-induced apoptosis in Jurkat cells. Cytometry A 2007; 71:668-74. [PMID: 17654655 DOI: 10.1002/cyto.a.20428] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [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: 12/21/2022]
Abstract
Measuring cytochrome c release during apoptosis provides valuable information about the nature and extent of apoptosis. Several years ago a flow cytometric method (based on selective permeabilization of the plasma membrane with digitonin) was developed that has advantages over other techniques. These experiments describe a comprehensive evaluation of that method. Apoptosis was triggered in Jurkat cells with staurosporine and then flow cytometry was used to measure three aspects of mitochondrial damage: (1) cytochrome c release (with the digitonin assay and a commercially available kit based on the same principle), using a DNA-binding dye to define cell cycle stage; (2) loss of mitochondrial cardiolipin, assessed by a decrease in 10 N-nonyl acridine orange (NAO) binding; and (3) loss of mitochondrial membrane potential, assessed by a decrease in tetramethylrhodamineethylester (TMRE) binding. The results from these three assays were compared with an antibody-based assay for cleaved caspase 3. The digitonin assay and the commercially available kit gave comparable results, showing that staurosporine caused cytochrome c release in all phases of the cell cycle and clearly defining those cells that had lost DNA due to internucleosomal DNA fragmentation. The pattern of fluorescence demonstrated that the mitochondrial apoptotic pathway was either the sole or the predominant pathway to be activated and that cytochrome c release in an individual cell was all-or-nothing. However, comparison with the other assays showed that the cytochrome c release assay underestimated the true extent of apoptosis. This was caused by the selective loss of some digitonin-treated apoptotic cells. The flow cytometry assay for cytochrome c release provides valuable information but it underestimates the percentage of apoptotic cells.
Collapse
Affiliation(s)
- Malcolm A King
- Fluorescence Activated Cell Sorting Laboratory, London Research Institute, Cancer Research UK, London WC2A 3PX, United Kingdom.
| | | | | |
Collapse
|
19
|
Bunkoczi G, Salah E, Filippakopoulos P, Fedorov O, Müller S, Sobott F, Parker SA, Zhang H, Min W, Turk BE, Knapp S. Structural and functional characterization of the human protein kinase ASK1. Structure 2007; 15:1215-26. [PMID: 17937911 PMCID: PMC2100151 DOI: 10.1016/j.str.2007.08.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 08/17/2007] [Accepted: 08/21/2007] [Indexed: 11/30/2022]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) plays an essential role in stress and immune response and has been linked to the development of several diseases. Here, we present the structure of the human ASK1 catalytic domain in complex with staurosporine. Analytical ultracentrifugation (AUC) and crystallographic analysis showed that ASK1 forms a tight dimer (K(d) approximately 0.2 microM) interacting in a head-to-tail fashion. We found that the ASK1 phosphorylation motifs differ from known ASK1 phosphorylation sites but correspond well to autophosphorylation sites identified by mass spectrometry. Reporter gene assays showed that all three identified in vitro autophosphorylation sites (Thr813, Thr838, Thr842) regulate ASK1 signaling, but site-directed mutants showed catalytic activities similar to wild-type ASK1, suggesting a regulatory mechanism independent of ASK1 kinase activity. The determined high-resolution structure of ASK1 and identified ATP mimetic inhibitors will provide a first starting point for the further development of selective inhibitors.
Collapse
Affiliation(s)
- Gabor Bunkoczi
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Eidarus Salah
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Panagis Filippakopoulos
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Oleg Fedorov
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Susanne Müller
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Frank Sobott
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| | - Sirlester A. Parker
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Haifeng Zhang
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Wang Min
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Benjamin E. Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Stefan Knapp
- University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom
| |
Collapse
|
20
|
Gjørret JO, Fabian D, Avery B, Maddox-Hyttel P. Active caspase-3 and ultrastructural evidence of apoptosis in spontaneous and induced cell death in bovine in vitro produced pre-implantation embryos. Mol Reprod Dev 2007; 74:961-71. [PMID: 17393434 DOI: 10.1002/mrd.20714] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this study we investigated chronological onset and involvement of active caspase-3, apoptotic nuclear morphology, and TUNEL-labeling, as well as ultrastructural evidence of apoptosis, in both spontaneous and induced cell death during pre-implantation development of bovine in vitro produced embryos. Pre-implantation embryos (2-cell to Day 8 blastocysts) were cultured with either no supplementation (untreated) or with 10 microM staurosporine for 24 hr (treated). Embryos were subjected to immunohistochemical staining of active caspase-3, TUNEL-reaction for detection of DNA degradation and DAPI staining for detection of apoptotic nuclear morphology, and subjected to fluorescence microscopy. Additionally, treated and untreated blastocysts were fixed and processed for ultrastructural identification of apoptosis. Untreated embryos revealed no apoptotic features at 2- and 4-cell stages. However, active caspase-3 and apoptotic nuclear morphology were observed in an untreated 8-cell stage, and TUNEL-labeling was observed from the 16-cell stage. Blastomeres concurrently displaying all apoptotic features were present in a few embryos at 16-cell and morula stages and in all blastocysts. All three features were observed from the 8-cell stage in treated embryos, and blastomeres with apoptotic features appeared more numerous in treated than in untreated embryos. Ultrastructural evidence of apoptosis occurred with a comparable distribution pattern as apoptotic features detected by fluorescence microscopy in both treated and untreated blastocysts. Activation of caspase-3 is likely involved in both spontaneous and induced apoptosis in bovine pre-implantation embryos, and immunohistochemical staining of active caspase-3 may be used in combination with other markers to identify apoptosis in pre-implantation embryos.
Collapse
|
21
|
Abstract
The authors present a fluorescence lifetime-based kinase binding assay that identifies and characterizes compounds that bind to the adenosine triphosphate (ATP)-binding pocket of a range of tyrosine and serine/threonine kinases. The assay is based on displacement of an Alexa Fluor 647 conjugate of staurosporine from the ATP-binding site of a kinase, which is detected by a change in the fluorescence lifetime of the probe between the free (displaced) and kinase-bound states. The authors screened 257 kinases for specific binding and displacement of the Alexa Fluor 647-staurosporine probe and found that approximately half of the kinases tested could potentially be assayed with this method. They present inhibitor binding data against 4 selected serine/threonine kinases and 4 selected tyrosine kinases, using 6 commonly used kinase inhibitors. Two of these kinases were chosen for further studies, in which inhibitor binding data were compared to inhibition of kinase activity using 2 separate activity assay formats. Rank-order potencies of compounds were similar, but not identical, between the binding and activity assays. It was postulated that these differences could be caused by the fact that the assays are measuring distinct phenomena, namely, activity versus binding, and in a purified recombinant kinase preparation, there can exist a mixture of active and nonactivated kinases. To explore this possibility, the authors compared binding affinity for the probe using 2 kinases in their respective nonactivated and activated (phosphorylated) forms and found a kinase-dependent difference between the 2 forms. This assay format therefore represents a simple method for the identification and characterization of small-molecule kinase inhibitors that may be useful in screening a wide range of kinases and may be useful in identifying small molecules that bind to kinases in their active or nonactivated states.
Collapse
|
22
|
Debierre-Grockiego F, Hippe D, Schwarz RT, Lüder CGK. Toxoplasma gondii glycosylphosphatidylinositols are not involved in T. gondii-induced host cell survival. Apoptosis 2007; 12:781-90. [PMID: 17252196 DOI: 10.1007/s10495-006-0038-4] [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: 10/23/2022]
Abstract
Toxoplasma gondii is an intracellular parasite able to both promote and inhibit apoptosis. T. gondii renders infected cells resistant to programmed cell death induced by multiple apoptotic triggers. On the other hand, increased apoptosis of immune cells after in vivo infection with T. gondii may suppress the immune response to the parasite. Glycosylphosphatidylinositol (GPI)-anchored proteins dominate the surface of T. gondii tachyzoites and GPIs are involved in the pathogenicity of protozoan parasites. In this report, we determine if GPIs are responsible for inhibition or induction of host cell apoptosis. We show here that T. gondii GPIs fail to block apoptosis that was triggered in human-derived cells via extrinsic or intrinsic apoptotic pathways. Furthermore, characteristics of apoptosis, e.g. caspase-3/7 activity, phosphatidylserine exposition at the cell surface or DNA strand breaks, were not observed in the presence of T. gondii GPIs. These results indicate that T. gondii GPIs are not involved in survival or in apoptosis of host cells. This absence of effect on apoptosis could be a feature common to GPIs of other parasites.
Collapse
|
23
|
Liu DS, Krebs CE, Liu SJ. Proliferation of human breast cancer cells and anti-cancer action of doxorubicin and vinblastine are independent of PKC-α. J Cell Biochem 2007; 101:517-28. [PMID: 17171646 DOI: 10.1002/jcb.21202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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: 11/10/2022]
Abstract
Protein kinase C (PKC) has been considered for a potential target of anticancer chemotherapy. PKC-alpha has been associated with growth and metastasis of some cancer cells. However, the role of PKC-alpha in human breast cancer cell proliferation and anticancer chemotherapy remains unclear. In this study, we examined whether alterations of PKC-alpha by phorbol esters and PKC inhibitors could affect proliferation of human breast cancer MCF-7 cells and the cytotoxic effect of chemotherapeutic agents. Exposure for 24 h to doxorubicin (DOX) and vinblastine (VIN) caused a concentration-dependent reduction in proliferation of MCF-7 cells. However, these two anticancer drugs altered cellular morphology and growth pattern in distinct manners. Phorbol 12,13-dibutyrate (PDBu, 100 nM), which enhanced activities of PKC-alpha, increased cancer cell proliferation and attenuated VIN (1 microM)-induced cytotoxicity. These effects were not affected in the presence of 10 nM staurosporine. Phorbol myristate acetate (PMA, 100 nM) that completely depleted PKC-alpha also enhanced cancer cell proliferation and attenuated VIN-induced cytotoxicity. Three potent PKC inhibitors, staurosporine (10 nM), chelerythrine (5 microM) and bisindolylmaleimide-I (100 nM), had no significant effect on MCF-7 cell proliferation; staurosporine and chelerythrine, but not bisindolylmaleimide-I, attenuated VIN-induced cytotoxicity. Moreover, neither phorbol esters nor PKC inhibitors had an effect on cytotoxic effects of DOX (1 microM) on MCF-7 cell proliferation. Thus, these data suggest that MCF-7 cell proliferation or the anti-cancer action of DOX and VIN on breast cancer cells is independent of PKC-alpha.
Collapse
Affiliation(s)
- Daniel Sd Liu
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | | |
Collapse
|
24
|
Sunyach C, Cisse MA, da Costa CA, Vincent B, Checler F. The C-terminal products of cellular prion protein processing, C1 and C2, exert distinct influence on p53-dependent staurosporine-induced caspase-3 activation. J Biol Chem 2006; 282:1956-63. [PMID: 17121821 DOI: 10.1074/jbc.m609663200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [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: 01/31/2023] Open
Abstract
The cellular prion protein (PrP(c)) undergoes various endopro-teolytic attacks within its N-terminal domain, leading to the production of C-terminal fragments (C) tethered to the plasma membrane and soluble N-terminal peptides (N). One of these cleavages occurs at position 110/111, thereby generating C1 and N1 products. We have reported that disintegrins ADAM-10, -9, and -17 participate either directly or indirectly to this proteolytic event. An alternative proteolytic event taking place around residue 90 yields C2 and N2 fragments. The putative function of these proteolytic fragments remained to be established. We have set up two novel human embryonic kidney 293 cell lines stably overexpressing either C1 or C2. We show that C1 potentiates staurosporine-induced caspase-3 activation through a p53-dependent mechanism. Thus, C1 positively controls p53 transcription and mRNA levels and increases p53-like immunoreactivity and activity. C1-induced caspase-3 activation remained unaffected by the blockade of endocytosis in HEK 293 cells and was abolished in p53-deficient fibroblasts. Conversely, overexpression of the C2 fragment did not significantly sensitize HEK 293 cells to apoptotic stimuli and did not modify p53 mRNA levels or activity. Therefore, the nature of the proteolytic cleavage taking place on PrP(c) yielded C-terminal catabolites with distinct function and could be seen as a switch mechanism controlling the function of the PrP(c) in cell survival.
Collapse
Affiliation(s)
- Claire Sunyach
- Institut de Pharmacologie Moleculaire et cellulaire du CNRS, UMR6097, Université Nice-Sophia-Antipolis, Equipe labellisée Fondation pour la Recherche Médicale, 660 route des Lucioles, Sophia-Antipolis, 06560 Valbonne, France
| | | | | | | | | |
Collapse
|
25
|
Tang H, Mayersohn M. On the observed large interspecies overprediction of human clearance ("vertical allometry") of UCN-01: further support for a proposed model based on plasma protein binding. J Clin Pharmacol 2006; 46:398-400. [PMID: 16554445 DOI: 10.1177/0091270005285457] [Citation(s) in RCA: 13] [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: 11/16/2022]
Abstract
The prediction of a human clearance (CL) value for UCN-01, an extreme example of vertical allometry (a large overprediction by allometric scaling), was examined using commonly used simple allometry and the "rule of exponents," as well as a newly proposed model, which quantitatively incorporates plasma protein-binding information from rats and humans. Simple allometry and the rule of exponents were shown to overpredict the human CL value of UCN-01 by about 5000- and 1750-fold, respectively. The new model incorporating the ratio of fraction unbound between rats and humans improved the prediction by about 20-fold compared to the rule of exponents. The model is expected to improve if a more accurate measurement of the unbound fraction in human plasma is obtained. The prediction of volume distribution for UCN-01 by allometric scaling was also shown to be dependent on the difference of fraction unbound between animal species and humans. In summary, plasma protein binding has been demonstrated to be an important measure for interspecies scaling of pharmacokinetics.
Collapse
Affiliation(s)
- Huadong Tang
- Bioanalytical Department, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965, USA.
| | | |
Collapse
|
26
|
Millward MJ, House C, Bowtell D, Webster L, Olver IN, Gore M, Copeman M, Lynch K, Yap A, Wang Y, Cohen PS, Zalcberg J. The multikinase inhibitor midostaurin (PKC412A) lacks activity in metastatic melanoma: a phase IIA clinical and biologic study. Br J Cancer 2006; 95:829-34. [PMID: 16969355 PMCID: PMC2360547 DOI: 10.1038/sj.bjc.6603331] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Midostaurin (PKC412A), N-benzoyl-staurosporine, potently inhibits protein kinase C alpha (PKCalpha), VEGFR2, KIT, PDGFR and FLT3 tyrosine kinases. In mice, midostaurin slows growth and delays lung metastasis of melanoma cell lines. We aimed to test midostaurin's safety, efficacy and biologic activity in a Phase IIA clinical trial in patients with metastatic melanoma. Seventeen patients with advanced metastatic melanoma received midostaurin 75 mg p.o. t.i.d., unless toxicity or disease progression supervened. Patient safety was assessed weekly, and tumour response was assessed clinically or by CT. Tumour biopsies and plasma samples obtained at entry and after 4 weeks were analysed for midostaurin concentration, PKC activity and multidrug resistance. No tumour responses were seen. Two (12%) patients had stable disease for 50 and 85 days, with minor response in one. The median overall survival was 43 days. Seven (41%) discontinued treatment with potential toxicity, including nausea, vomiting, diarrhoea and/or fatigue. One patient had >50% reduction in PKC activity. Tumour biopsies showed two PKC isoforms relatively insensitive to midostaurin, out of three patients tested. No modulation of multidrug resistance was demonstrated. At this dose schedule, midostaurin did not show clinical or biologic activity against metastatic melanoma. This negative trial reinforces the importance of correlating biologic and clinical responses in early clinical trials of targeted therapies.
Collapse
Affiliation(s)
- M J Millward
- Peter MacCallum Cancer Institute, Melbourne, Victoria, Australia.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Campos CBL, Paim BA, Cosso RG, Castilho RF, Rottenberg H, Vercesi AE. Method for monitoring of mitochondrial cytochrome c release during cell death: Immunodetection of cytochrome c by flow cytometry after selective permeabilization of the plasma membrane. Cytometry A 2006; 69:515-23. [PMID: 16680678 DOI: 10.1002/cyto.a.20273] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Cytochrome c release from mitochondria to cytosol is a hallmark of apoptosis and is used to characterize the mitochondria-dependent pathway of this type of cell death. Techniques currently used to measure cytochrome c release, Western blot and fluorescence microscopy of immunolabeled cells, are time-consuming and inaccurate, and the latter is still limited by sample size. METHODS We developed a rapid and reliable technique to detect cytochrome c release during drug-induced apoptosis, using flow cytometry. Plasma membrane of apoptotic HL-60 cells and thymocytes, treated with staurosporine and dexamethasone, respectively, were selectively permeabilized by digitonin at a low concentration. The released cytochrome c was quickly washed out from cells and that which remained in the mitochondria was immunolabeled after fixing the cells. RESULTS The fraction of cells that retained their mitochondrial cytochrome c, or the highly fluorescent cells, gradually decreased so that after 4-8 h of drug treatment almost all the cells lost their cytochrome c and emerged as a population of low fluorescent cells. This was confirmed by parallel fluorescence microscopy of cells immunolabeled for cytochrome c. CONCLUSIONS This technique allows the analysis of cytochrome c release from mitochondria of a large number of apoptotic cells in a short period of time and is proposed as an alternative to the methods currently used for this same purpose.
Collapse
Affiliation(s)
- Claudia B L Campos
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Brazil
| | | | | | | | | | | |
Collapse
|
28
|
Abstract
High mobility group box 1 protein (HMGB1) is a non-histone nuclear protein with dual function. Inside the cell, HMGB1 binds DNA and regulates transcription, whereas outside the cell, it serves as a cytokine and mediates the late effects of LPS. The movement of HMGB1 into the extracellular space has been demonstrated for macrophages stimulated with LPS as well as cells undergoing necrosis but not apoptosis. The differential release of HMGB1 during death processes could reflect the structure of chromatin in these settings as well as the mechanisms for HMGB1 translocation. Since apoptotic cells can release some nuclear molecules such as DNA to which HMGB1 can bind, we therefore investigated whether HMGB1 release can occur during apoptosis as well as necrosis. For this purpose, Jurkat cells were treated with chemical inducers of apoptosis (staurosporine, etoposide, or camptothecin), and HMGB1 release into the medium was assessed by Western blotting. Results of these experiments indicate that HMGB1 appears in the media of apoptotic Jurkat cells in a time-dependent manner and that this release can be reduced by Z-VAD-fmk. Panc-1 and U937 cells treated with these agents showed similar release. In addition, HeLa cells induced to undergo apoptosis showed HMGB1 release. Furthermore, we showed using confocal microscopy that HMGB1 and DNA change their nuclear location in Jurkat cells undergoing apoptosis. Together, these studies indicate that HMGB1 release can occur during the course of apoptosis as well as necrosis and suggest that the release process may vary with cell type.
Collapse
Affiliation(s)
- Charles W Bell
- Division of Rheumatology and Immunology, Duke University Medical Center, and Medical Research Service, Durham Veterans Affairs Hospital, Durham, North Carolina 27705, USA
| | | | | | | |
Collapse
|
29
|
Kinoshita T, Matsubara M, Ishiguro H, Okita K, Tada T. Structure of human Fyn kinase domain complexed with staurosporine. Biochem Biophys Res Commun 2006; 346:840-4. [PMID: 16782058 DOI: 10.1016/j.bbrc.2006.05.212] [Citation(s) in RCA: 47] [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] [Received: 05/23/2006] [Accepted: 05/30/2006] [Indexed: 11/15/2022]
Abstract
The tyrosine kinase Fyn is a member of the Src kinase family. Besides the role of Fyn in T cell signal transduction in concert with Lck, its excess activity in the brain is involved with conditions such as Alzheimer's and Parkinson's diseases. Therefore, inhibition of Fyn kinase may help counteract these nervous system disorders. Here, we solved the crystal structure of the human Fyn kinase domain complexed with staurosporine, a potent kinase inhibitor, at 2.8 A resolution. Staurosporine binds to the ATP-binding site of Fyn in a similar manner as in the Lck- and Csk-complexes. The small structural differences in the staurosporine-binding and/or -unbinding region among the three kinase domains may help obtaining the selective inhibitors against the respective kinases.
Collapse
Affiliation(s)
- Takayoshi Kinoshita
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Gakuencho 1-1, Sakai, Osaka 599-8531, Japan.
| | | | | | | | | |
Collapse
|
30
|
Landrieu I, Lacosse L, Leroy A, Wieruszeski JM, Trivelli X, Sillen A, Sibille N, Schwalbe H, Saxena K, Langer T, Lippens G. NMR analysis of a Tau phosphorylation pattern. J Am Chem Soc 2006; 128:3575-83. [PMID: 16536530 DOI: 10.1021/ja054656+] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [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: 11/28/2022]
Abstract
The phosphorylation of the neuronal Tau protein modulates both its physiological role of microtubule binding and its aggregation into paired helical fragments observed in Alzheimer's diseased neurons. However, detailed knowledge of the role of phosphorylation at specific sites has been hampered by the analytical difficulties to evaluate the level of site-specific phosphate incorporation. Even with recombinant kinases, mass spectrometry and immunodetection are not evident for determining the full phosphorylation pattern in a qualitative and quantitative manner. We show here that heteronuclear NMR spectroscopy on a 15N labeled Tau sample modified by the cAMP dependent kinase allows identification of all phosphorylation sites, measures their level of phosphate integration, and yields kinetic data for the enzymatic modification of the individual sites. Filtering through the 15N label discards the necessity of any further sample purification and allows the in situ monitoring of kinase activity at selected sites. We finally demonstrate that the NMR approach can equally be used to evaluate potential kinase inhibitors in a straightforward manner.
Collapse
|
31
|
Harmalkar MN, Shirsat NV. Staurosporine-induced growth inhibition of glioma cells is accompanied by altered expression of cyclins, CDKs and CDK inhibitors. Neurochem Res 2006; 31:685-92. [PMID: 16770740 DOI: 10.1007/s11064-006-9068-0] [Citation(s) in RCA: 10] [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] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
Staurosporine was found to bring about complete growth inhibition of human glioma cell lines. U87 MG cells were arrested in S phase while U373 MG cells in G2/M phase on staurosporine treatment. Consistent with this observation, no change in G1 phase regulators viz., Cyclin D1, D3 and CDK4 was seen on staurosporine treatment. The levels of CDK2, CDC2, Cyclin A and Cyclin B proteins decreased, while the levels of CDK inhibitors viz., p21 and p27 were found to increase on staurosporine treatment. The mRNA levels of CDK2 and CDC2 genes were also found to decrease on staurosporine treatment. Thus apart from staurosporine's known direct inhibitory effect on CDK2 and CDC2 activities, staurosporine was found to down-regulate activities of these two kinases by modulating the expression of the kinases themselves as well that of their activating partners (Cyclins) and their inhibitors.
Collapse
Affiliation(s)
- Mugdha N Harmalkar
- Neurooncology, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai 410208, India
| | | |
Collapse
|
32
|
Woclawek-Potocka I, Bober A, Korzekwa A, Okuda K, Skarzynski DJ. Equol and para-ethyl-phenol stimulate prostaglandin F(2alpha) secretion in bovine corpus luteum: intracellular mechanisms of action. Prostaglandins Other Lipid Mediat 2006; 79:287-97. [PMID: 16647642 DOI: 10.1016/j.prostaglandins.2006.03.003] [Citation(s) in RCA: 13] [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] [Received: 02/11/2006] [Revised: 03/03/2006] [Accepted: 03/06/2006] [Indexed: 01/02/2023]
Abstract
Corpus luteum (CL) is a reproductive gland that plays a crucial endocrine role in the regulation of the estrous cycle, fertility, and pregnancy in cattle. The main function of CL is secretion of progesterone (P4), an important hormone for establishment a successful pregnancy, whereas prostaglandin F(2alpha) (PGF(2alpha)), 17beta-estradiol (E(2)) and testosterone (T) are implicated in the regulation of luteolysis. It has been shown that phytoestrogens may disrupt numerous reproductive functions on several levels of regulation and via different intracellular mechanisms. Using a cell-culture system of steroidogenic cells of the bovine CL, we determined effects of active phytoestrogen metabolites (equol and para-ethyl-phenol) on PGF(2alpha), P4, and T synthesis in steroidogenic CL cells. Moreover, we examined the intracellular mechanisms of phytoestrogen metabolite actions. Phytoestrogen metabolites did not affect P4 production in steroidogenic CL cells. However, PGF(2alpha) and T were significantly stimulated by metabolites of phytoestrogens in the bovine steroidogenic CL cells. To study the intracellular mechanism of endogenous E(2) and phytoestrogen metabolites action, steroidogenic cells were preincubated with a phospholipase C inhibitor (U73122), a protein kinase C inhibitor (staurosporine), an estrogen receptor antagonist (ICI) and a transcription inhibitor (actinomycin D) for 0.5h, and then stimulated with para-ethyl-phenol, equol or E(2). Only U73122 and staurosporine totally reduced the stimulatory effect of E(2) on PGF(2alpha) production by the cells. ICI and actinomycin D only partially reduced E(2) action on CL cells. In contrast, the stimulatory effect of phytoestrogen metabolites was totally inhibited by ICI and actinomycin D. Moreover, in contrast to E(2) action, phytoestrogen metabolites did not cause intracellular calcium mobilization in the cells. The present study demonstrated that phytoestrogen metabolites stimulate PGF(2alpha) secretion in steroidogenic cells of the bovine CL via the estrogen receptor-dependent, genomic pathway.
Collapse
Affiliation(s)
- Izabela Woclawek-Potocka
- Department of Reproductive Immunology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-747 Olsztyn, Poland
| | | | | | | | | |
Collapse
|
33
|
Abstract
Rapid CD4+ lymphocyte depletion due to cell death caused by HIV infection is one of the hallmarks of acquired immunodeficiency syndrome. HIV-1 viral protein R (Vpr) induces apoptosis and is believed to contribute to CD4+ lymphocyte depletion. Thus, identification of cellular factors that potentially counteract this detrimental viral effect will not only help us to understand the molecular action of Vpr but also to design future antiviral therapies. In this report, we describe identification of elongation factor 2 (EF2) as such a cellular factor. Specifically, EF2 protein level is responsive to vpr gene expression; it is able to suppress Vpr-induced apoptosis when it is overproduced beyond its physiological level. EF2 was initially identified through a genome-wide multicopy suppressor search for Vpr-induced apoptosis in a fission yeast model system. Overproduction of fission yeast Ef2 completely abolishes Vpr-induced cell killing in fission yeast. Similarly, overexpression of the human homologue of yeast Ef2 in a neuroblastoma SKN-SH cell line and two CD4+ H9 and CEM-SS T-cell lines also blocked Vpr-induced apoptosis. The anti-apoptotic property of EF2 is demonstrated by its ability to suppress caspase 9 and caspase 3-mediated apoptosis induced by Vpr. In addition, it also reduces cytochrome c release induced by Vpr, staurosporine and TNFalpha. The fact that overproduction of EF2 blocks Vpr-induced cell death both in fission yeast and human cells, suggested that EF2 posses a highly conserved anti-apoptotic activity. Moreover, the responsive elevation of EF2 to Vpr suggests a possible host innate antiviral response.
Collapse
Affiliation(s)
- S Zelivianski
- Children's Memorial Research Center, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA
| | | | | | | | | |
Collapse
|
34
|
Karlsson R, Katsamba PS, Nordin H, Pol E, Myszka DG. Analyzing a kinetic titration series using affinity biosensors. Anal Biochem 2006; 349:136-47. [PMID: 16337141 DOI: 10.1016/j.ab.2005.09.034] [Citation(s) in RCA: 298] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Revised: 09/22/2005] [Accepted: 09/22/2005] [Indexed: 11/20/2022]
Abstract
The classical method of measuring binding constants with affinity-based biosensors involves testing several analyte concentrations over the same ligand surface and regenerating the surface between binding cycles. Here we describe an alternative approach to collecting kinetic binding data, which we call "kinetic titration." This method involves sequentially injecting an analyte concentration series without any regeneration steps. Through a combination of simulation and experimentation, we show that this method can be as robust as the classical method of analysis. In addition, kinetic titrations can be more efficient than the conventional data collection method and allow us to fully characterize analyte binding to ligand surfaces that are difficult to regenerate.
Collapse
|
35
|
Abstract
We have previously identified transcription factors binding to the proximal promoter region of the human COL1A2 gene that are essential for promoter activity. Two regions in the proximal promoter, the CCAAT-element and the CME bind the CCAAT-binding factor and an as yet uncharacterized DNA-binding protein, respectively. In this study we show that phosphorylation of both the CCAAT-binding and CME-binding proteins are essential for DNA-binding activity. While the binding of the CCAAT-binding proteins to the COL1A2 proximal promoter was inhibited after treatment of nuclear proteins with calf intestinal phosphatase, PP2A treatment had a significant inhibitory effect on the binding of the CME-binding proteins. The treatment of type I collagen producing fibroblasts, CT-1, with the kinase inhibitor, staurosporine, interfered with DNA-protein interactions on both elements on the COL1A2 proximal promoter. This inhibition was associated with a significant decrease in both endogenous COL1A2 gene expression as observed by northern blot analysis and proximal promoter activity as assayed in transient transfection assays. Our results suggest that the phosphorylation of transcription factors interacting with the COL1A2 proximal promoter is essential for both DNA binding and for the expression of this gene.
Collapse
Affiliation(s)
- Virna D Leaner
- Division of Medical Biochemistry, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, South Africa
| | | |
Collapse
|
36
|
Um M, Lodish HF. Antiapoptotic effects of erythropoietin in differentiated neuroblastoma SH-SY5Y cells require activation of both the STAT5 and AKT signaling pathways. J Biol Chem 2006; 281:5648-56. [PMID: 16407271 DOI: 10.1074/jbc.m510943200] [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] [Indexed: 11/06/2022] Open
Abstract
The hematopoietic cytokine erythropoietin (Epo) prevents neuronal death during ischemic events in the brain and in neurodegenerative diseases, presumably through its antiapoptotic effects. To explore the role of different signaling pathways in Epo-mediated antiapoptotic effects in differentiated human neuroblastoma SH-SY5Y cells, we employed a prolactin receptor (PrlR)/erythropoietin receptor (EpoR) chimera system, in which binding of prolactin (Prl) to the extracellular domain activates EpoR signaling in the cytosol. On induction of apoptosis by staurosporine, Prl supports survival of the SH-SY5Y cells expressing the wild-type PrlR/EpoR chimera. In these cells Prl treatment strongly activates the STAT5, AKT, and MAPK signaling pathways and induces weak activation of the p65 NF-kappaB factor. Selective mutation of the eight tyrosine residues of the EpoR cytoplasmic domain results in impaired or absent activation of either STAT5 (mutation of Tyr(343)) or AKT (mutation of Tyr(479)) or both (mutation of all eight tyrosine residues). Most interestingly, Prl treatment does not prevent apoptosis in cells expressing mutant PrlR/EpoR chimeras in which either the STAT5 or the AKT signaling pathways are not activated. In contrast, ERK 1/2 is fully activated by all mutant PrlR/EpoR chimeras, comparable with the level seen with the wild-type PrlR/EpoR chimera, implying that activation of the MAPK signaling pathway per se is not sufficient for antiapoptotic activity. Therefore, the antiapoptotic effects of Epo in neuronal cells require the combinatorial activation of multiple signaling pathways, including STAT5, AKT, and potentially MAPK as well, in a manner similar to that observed in hematopoietic cells.
Collapse
Affiliation(s)
- Moonkyoung Um
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | | |
Collapse
|
37
|
Zamaraeva MV, Sabirov RZ, Maeno E, Ando-Akatsuka Y, Bessonova SV, Okada Y. Cells die with increased cytosolic ATP during apoptosis: a bioluminescence study with intracellular luciferase. Cell Death Differ 2005; 12:1390-7. [PMID: 15905877 DOI: 10.1038/sj.cdd.4401661] [Citation(s) in RCA: 236] [Impact Index Per Article: 12.4] [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
Apoptosis is a distinct form of cell death, which requires energy. Here, we made real-time continuous measurements of the cytosolic ATP level throughout the apoptotic process in intact HeLa, PC12 and U937 cells transfected with the firefly luciferase gene. Apoptotic stimuli (staurosporine (STS), tumor necrosis factor alpha (TNFalpha), etoposide) induced significant elevation of the cytosolic ATP level. The cytosolic ATP level remained at a higher level than in the control for up to 6 h during which activation of caspase-3 and internucleosomal DNA fragmentation took place. When the STS-induced ATP response was abolished by glucose deprivation-induced inhibition of glycolysis, both caspase activation and DNA laddering were completely inhibited. Annexin V-binding induced by STS or TNFalpha was largely suppressed by glycolysis inhibition. Thus, it is suggested that the cells die with increased cytosolic ATP, and elevation of cytosolic ATP level is a requisite to the apoptotic cell death process.
Collapse
Affiliation(s)
- M V Zamaraeva
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | | | | | | | | | | |
Collapse
|
38
|
Espinoza-Fonseca LM, Trujillo-Ferrara JG. Identification of multiple allosteric sites on the M1muscarinic acetylcholine receptor. FEBS Lett 2005; 579:6726-32. [PMID: 16310776 DOI: 10.1016/j.febslet.2005.10.069] [Citation(s) in RCA: 7] [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] [Received: 08/05/2005] [Revised: 10/11/2005] [Accepted: 10/27/2005] [Indexed: 10/25/2022]
Abstract
Staurosporine and four staurosporine derivatives were docked on the rhodopsin-based homology model of the M1 muscarinic acetylcholine receptor in order to localize the possible allosteric sites of this receptor. It was found that there were three major allosteric sites, two of which are located at the extracellular face of the receptor, and one in the intracellular domain of the receptor. In the present study, the localization of these binding sites is described for the first time. The present study confirms the existence of multiple allosteric sites on the M1 muscarinic receptor, and lays the ground for further experimental and computational analysis to better understand how muscarinic receptors are modulated via their allosteric sites. These findings will also help to design and develop novel drugs acting as allosteric modulators of the M1 receptor, which can be used in the treatment of the Alzheimer's disease.
Collapse
Affiliation(s)
- L Michel Espinoza-Fonseca
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | | |
Collapse
|
39
|
Kiesecker C, Zitron E, Scherer D, Lueck S, Bloehs R, Scholz EP, Pirot M, Kathöfer S, Thomas D, Kreye VAW, Kiehn J, Borst MM, Katus HA, Schoels W, Karle CA. Regulation of cardiac inwardly rectifying potassium current IK1 and Kir2.x channels by endothelin-1. J Mol Med (Berl) 2005; 84:46-56. [PMID: 16258766 DOI: 10.1007/s00109-005-0707-8] [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] [Received: 12/07/2004] [Accepted: 06/17/2005] [Indexed: 01/08/2023]
Abstract
To elucidate the ionic mechanism of endothelin-1 (ET-1)-induced focal ventricular tachyarrhythmias, the regulation of I(K1) and its main molecular correlates, Kir2.1, Kir2.2 and Kir2.3 channels, by ET-1 was investigated. Native I(K1) in human atrial cardiomyocytes was studied with whole-cell patch clamp. Human endothelin receptors were coexpressed with human Kir2.1, Kir2.2 and Kir2.3 channels in Xenopus oocytes. Currents were measured with a two-microelectrode voltage clamp. In human cardiomyocytes, ET-1 induced a marked inhibition of I(K1) that could be suppressed by the protein kinase C (PKC) inhibitor staurosporine. To investigate the molecular mechanisms underlying this regulation, we studied the coupling of ET(A) receptors to homomeric and heteromeric Kir2.1, Kir2.2 and Kir2.3 channels in the Xenopus oocyte expression system. ET(A) receptors coupled functionally to Kir2.2 and Kir2.3 channels but not to Kir2.1 channels. In Kir2.2 channels lacking functional PKC phosphorylation sites, the inhibitory effect was abolished. The inhibition of Kir2.3 currents could be suppressed by the PKC inhibitors staurosporine and chelerythrine. The coupling of ET(A) receptors to heteromeric Kir2.1/Kir2.2 and Kir2.2/Kir2.3 channels resulted in a strong inhibition of currents comparable with the effect observed in Kir2.2 homomers. Surprisingly, in heteromeric Kir2.1/Kir2.3 channels, no effect was observed. ET-1 inhibits human cardiac I(K1) current via a PKC-mediated phosphorylation of Kir2.2 channel subunits and additional regulatory effects on Kir2.3 channels. This mechanism may contribute to the intrinsic arrhythmogenic potential of ET-1.
Collapse
Affiliation(s)
- Claudia Kiesecker
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Nahon E, Israelson A, Abu-Hamad S, Varda SB. Fluoxetine (Prozac) interaction with the mitochondrial voltage-dependent anion channel and protection against apoptotic cell death. FEBS Lett 2005; 579:5105-10. [PMID: 16139271 DOI: 10.1016/j.febslet.2005.08.020] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [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: 06/20/2005] [Revised: 08/05/2005] [Accepted: 08/10/2005] [Indexed: 11/19/2022]
Abstract
Fluoxetine (Prozac) is a potent antidepressant compound inhibiting serotonin reuptake, but also Na+, K+ and Ca2+ channels and reported to both trigger and prevent apoptosis. Recently, fluoxetine was found to increase the voltage sensitivity of the mitochondrial voltage-dependent anion channel (VDAC). VDAC which functions in transporting metabolites across the mitochondria also plays a crucial role in apoptosis. Here, we demonstrate that fluoxetine interacted with VDAC and decreased its conductance. Fluoxetine inhibited the opening of the mitochondrial permeability transition pore, the release of cytochrome c, and protected against staurosporine-induced apoptotic cell death. These findings may explain some of the reported fluoxetine side effects.
Collapse
Affiliation(s)
- Edna Nahon
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | | | | | | |
Collapse
|
41
|
Yamauchi M, Kusano H, Nakakura M, Kato Y. Reducing the impact of binding of UCN-01 to human alpha1-acid glycoprotein by encapsulation in liposomes. Biol Pharm Bull 2005; 28:1259-64. [PMID: 15997110 DOI: 10.1248/bpb.28.1259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [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: 11/22/2022]
Abstract
A liposomal formulation of UCN-01 was studied to prevent binding of drug to human alpha1-acid glycoprotein (hAGP). The release of drug from liposomes added to various media was investigated by monitoring the concentration of UCN-01 in different fractions. Protein bound UCN-01 was separated from liposomal UCN-01 and free UCN-01 by gel chromatography and the drug content in the fractions was measured by high-performance liquid chromatography. Also, the blood levels of hAGP bound drug and drug retained in liposomes were assessed after intravenous administration to rats of UCN-01 liposomes together with hAGP. In media containing hAGP, but not rat AGP, UCN-01 was released from liposomes. When UCN-01 liposomes were mixed with rat plasma plus hAGP, the UCN-01 in the liposomes was only gradually released so that some drug remained in the liposomes, and therefore not bound to hAGP, for up to 24 h. After the mixture of liposomal UCN-01 and hAGP was injected into rats, some UCN-01 was retained in liposomes for several hours. Encapsulation of UCN-01 into liposomes is an effective method of preventing binding of UCN-01 to hAGP.
Collapse
Affiliation(s)
- Masahiro Yamauchi
- Drug Formulation Research Laboratories, Pharmaceutical Research Center, Kyowa Hakko Kogyo Co., Ltd., Shizuoka, Japan.
| | | | | | | |
Collapse
|
42
|
May A, Zacharias M. Accounting for global protein deformability during protein-protein and protein-ligand docking. Biochim Biophys Acta 2005; 1754:225-31. [PMID: 16214429 DOI: 10.1016/j.bbapap.2005.07.045] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 07/20/2005] [Accepted: 07/21/2005] [Indexed: 11/20/2022]
Abstract
Computational docking methods are valuable tools aimed to simplify the costly process of drug development and improvement. Most current approaches assume a rigid receptor structure to allow virtual screening of large numbers of possible ligands and putative binding sites on a receptor molecule. However, inclusion of receptor flexibility can be of critical importance since binding of a ligand can lead to changes in the receptor protein conformation that are sterically necessary to accommodate a ligand. Recent approaches to efficiently account for receptor flexibility during docking simulations are reviewed. In particular, accounting efficiently for global conformational changes of the protein backbone during docking is a still challenging unsolved problem. An approximate method has recently been suggested that is based on relaxing the receptor conformation during docking in pre-calculated soft collective degrees of freedom (M. Zacharias, Rapid protein-ligand docking using soft modes from molecular dynamics simulations to account for protein deformability: binding of FK506 to FKBP, Proteins: Struct., Funct., Genet. 54 (2004) 759-767). Test applications on protein-protein docking and on docking the inhibitor staurosporine to the apo-form of cAMP-dependent protein kinase A catalytic domain indicate significant improvement of docking results compared to rigid docking at a very modest computational demand. Accounting for receptor conformational changes in pre-calculated global degrees of freedom might offer a promising route to improve systematic docking screening simulations.
Collapse
Affiliation(s)
- Andreas May
- Computational Biology, School of Engineering and Science, International University Bremen, Campus Ring 6, D-28759 Bremen, Germany
| | | |
Collapse
|
43
|
Ebel H, Günther T. Na+/Mg2+ antiport in erythrocytes of spontaneously hypertensive rats: role of Mg2+ in the pathogenesis of hypertension. Magnes Res 2005; 18:175-85. [PMID: 16259378] [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: 05/05/2023]
Abstract
Total Mg2+ content in plasma and erythrocytes did not significantly differ between WKY and SHR. Mg2+ efflux via Na+/Mg2+ antiport was 10% lower in non Mg(2+)-loaded erythrocytes of SHR than in WKY, and 16% lower in Mg(2+)-loaded erythrocytes of SHR. The activation of Na+/Mg2+ antiport in erythrocytes by Cl-, as tested by substitution of Cl- with SCN-, and the regulation of Na+/Mg2+ antiport by protein kinases, as tested by PMA and staurosporine, showed no differences between WKY and SHR. The reduction of Na+/Mg2+ antiport was explained by a reduction in the number of Na+/Mg2+ antiporter molecules in SHR erythrocytes. Mg2+ efflux in KCl medium by K+/Mg2+ antiport via the unspecific choline exchanger was not significantly reduced in SHR and was equally affected by PMA and staurosporine in WKY and SHR. An explanation for some controversial results, unchanged or reduced concentration of Mg2+ in serum, total Mg2+ and free Mg2+ in erythrocytes of SHR and patients with essential hypertension was proposed. The role of Na+/Mg2+ antiport and [Mg2+]i in the pathogenesis of experimental and clinical hypertension was discussed.
Collapse
Affiliation(s)
- H Ebel
- Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Institut für Klinische Physiologie, Berlin, Germany.
| | | |
Collapse
|
44
|
Luna-Medina R, Cortes-Canteli M, Alonso M, Santos A, Martínez A, Perez-Castillo A. Regulation of Inflammatory Response in Neural Cells in Vitro by Thiadiazolidinones Derivatives through Peroxisome Proliferator-activated Receptor γ Activation. J Biol Chem 2005; 280:21453-62. [PMID: 15817469 DOI: 10.1074/jbc.m414390200] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [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: 11/06/2022] Open
Abstract
In most neurodegenerative disorders, including multiple sclerosis, Parkinson disease, and Alzheimer disease, a massive neuronal cell death occurs as a consequence of an uncontrolled inflammatory response, where activated astrocytes and microglia and their cytotoxic agents play a crucial pathological role. Current treatments for these diseases are not effective. In the present study we investigate the effect of thiadiazolidinone derivatives, which have been recently suggested to play a role in neurodegenerative disorders. We have found that thiadiazolidinones are potent neuroprotector compounds. Thiadiazolidinones inhibited inflammatory activation of cultured brain astrocytes and microglia by diminishing lipopolysaccharide-induced interleukin 6, tumor necrosis factor alpha, inducible nitric-oxide synthase, and inducible cyclooxygenase type 2 expression. In addition, thiadiazolidinones inhibited tumor necrosis factor-alpha and nitric oxide production and, concomitantly, protected cortical neurons from cell death induced by the cell-free supernatant from activated microglia. The neuroprotective effects of thiadiazolidinones are completely inhibited by the peroxisome proliferator-activated receptor gamma antagonist GW9662. In contrast the glycogen synthase kinase 3beta inhibitor LiCl did not show any effect. These findings suggest that thiadiazolidinones potently attenuate lipopolysaccharide-induced neuroinflammation and reduces neuronal death by a mechanism dependent of peroxisome proliferator-activated receptor gamma activation.
Collapse
Affiliation(s)
- Rosario Luna-Medina
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas-Universidad Rutónoma de Madrid, 28029 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
45
|
Beattie JH, Owen HLH, Wallace SM, Arthur JR, Kwun IS, Hawksworth GM, Wallace HM. Metallothionein overexpression and resistance to toxic stress. Toxicol Lett 2005; 157:69-78. [PMID: 15795095 DOI: 10.1016/j.toxlet.2005.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [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: 11/19/2004] [Revised: 01/13/2005] [Accepted: 01/17/2005] [Indexed: 11/30/2022]
Abstract
Metallothionein (MT) protects against the harmful effects of a wide spectrum of stress factors. The most studied of these factors is cadmium, whose toxicity is reduced on sequestration by MT. However, there is poorer consensus in the literature about protection afforded by MT against stressors other than cadmium. In this study, a CHO-K1 cell line continuously overexpressing MT (MToex) was developed in order to evaluate the relative protection afforded by MT against different toxic agents. Cadmium was used as a positive control and, as expected, the MToex cells were more than 13-fold more resistant to the effects of cadmium chloride than were wild-type (WT) cells using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay (IC50 values of 10 and 132 microM for WT and MToex cells, respectively). In contrast, overexpression of MT afforded no protection against mercuric chloride, staurosporine and hydrogen peroxide (IC50 values of about 50, 11 and 925 microM, respectively). Cd and Hg uptake by MToex and WT cells exposed to 1-10 microM of metal chloride was similar and yet a significant amount of these metals was associated with the cytosol MT fraction in the MToex cells but not in the WT cells. From this study it can be concluded that while MT overexpression protects against Cd toxicity, it has no influence on Hg, staurosporine or hydrogen peroxide toxicity and it is proposed that this reflects mechanistic differences of toxicity or depletion of labile intracellular zinc by the presence of excess binding ligand in the form of MT.
Collapse
Affiliation(s)
- John H Beattie
- Division of Cellular Integrity, Rowett Research Institute, Bucksburn, Aberdeen, UK.
| | | | | | | | | | | | | |
Collapse
|
46
|
Annis DA, Nazef N, Chuang CC, Scott MP, Nash HM. A general technique to rank protein-ligand binding affinities and determine allosteric versus direct binding site competition in compound mixtures. J Am Chem Soc 2005; 126:15495-503. [PMID: 15563178 DOI: 10.1021/ja048365x] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [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: 11/29/2022]
Abstract
To realize the full potential of combinatorial chemistry-based drug discovery, generic and efficient tools must be developed that apply the strengths of diversity-oriented chemical synthesis to the identification and optimization of lead compounds for disease-associated protein targets. We report an affinity selection-mass spectrometry (AS-MS) method for protein-ligand affinity ranking and the classification of ligands by binding site. The method incorporates the following steps: (1) an affinity selection stage, where protein-binding compounds are selected from pools of ligands in the presence of varying concentrations of a competitor ligand, (2) a first chromatography stage to separate unbound ligands from protein-ligand complexes, and (3) a second chromatography stage to dissociate the ligands from the complexes for identification and quantification by MS. The ability of the competitor ligand to displace a target-bound library member, as measured by MS, reveals the binding site classification and affinity ranking of the mixture components. The technique requires no radiolabel incorporation or direct biochemical assay, no modification or immobilization of the compounds or target protein, and all reaction components, including any buffers or cofactors required for protein stability, are free in solution. We demonstrate the method for several compounds of wide structural variety against representatives of the most important protein classes in contemporary drug discovery, including novel ATP-competitive and allosteric inhibitors of the Akt-1 (PKB) and Zap-70 kinases, and previously undisclosed antagonists of the M(2) muscarinic acetylcholine receptor, a G-protein coupled receptor (GPCR). The theoretical basis of the technique is analyzed mathematically, allowing quantitative estimation of binding affinities and, in the case of allosteric interaction, absolute determination of binding cooperativity. The method is readily applicable to high-throughput screening hit triage, combinatorial library-based affinity optimization, and developing structure-activity relationships among multiple ligands to a given receptor.
Collapse
Affiliation(s)
- D Allen Annis
- NeoGenesis Pharmaceuticals Inc., 840 Memorial Drive, Cambridge, MA 02139, USA.
| | | | | | | | | |
Collapse
|
47
|
Abstract
We apply our recently developed metadynamics method to the docking of ligands on flexible receptors in water solution. This method mimics the real dynamics of a ligand exiting or entering an enzyme and in so doing reconstructs the free energy surface. We apply it to four docking cases: beta-trypsin/benzamidine, beta-trypsin/chlorobenzamidine, immunoglobulin McPC-603/phosphocholine, and cyclin-dependent kinase 2/staurosporine. In every case studied, the method is able to predict the docked geometry and the free energy of docking. Its added value with respect to many other available methods is that it reconstructs the complete free energy surface, including all the relevant minima and the barriers between them.
Collapse
Affiliation(s)
- Francesco Luigi Gervasio
- Computational Science, Department of Chemistry and Applied Biosciences, ETH Zürich, USI Campus, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.
| | | | | |
Collapse
|
48
|
Jacobs MD, Black J, Futer O, Swenson L, Hare B, Fleming M, Saxena K. Pim-1 Ligand-bound Structures Reveal the Mechanism of Serine/Threonine Kinase Inhibition by LY294002. J Biol Chem 2005; 280:13728-34. [PMID: 15657054 DOI: 10.1074/jbc.m413155200] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [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] Open
Abstract
Pim-1 is an oncogene-encoded serine/threonine kinase primarily expressed in hematopoietic and germ cell lines. Pim-1 kinase was originally identified in Maloney murine leukemia virus-induced T-cell lymphomas and is associated with multiple cellular functions such as proliferation, survival, differentiation, apoptosis, and tumorigenesis (Wang, Z., Bhattacharya, N., Weaver, M., Petersen, K., Meyer, M., Gapter, L., and Magnuson, N. S. (2001) J. Vet. Sci. 2, 167-179). The crystal structures of Pim-1 complexed with staurosporine and adenosine were determined. Although a typical two-domain serine/threonine protein kinase fold is observed, the inter-domain hinge region is unusual in both sequence and conformation; a two-residue insertion causes the hinge to bulge away from the ATP-binding pocket, and a proline residue in the hinge removes a conserved main chain hydrogen bond donor. Without this hydrogen bond, van der Waals interactions with the hinge serve to position the ligand. The hinge region of Pim-1 resembles that of phosphatidylinositol 3-kinase more closely than it does other protein kinases. Although the phosphatidylinositol 3-kinase inhibitor LY294002 also inhibits Pim-1, the structure of the LY294002.Pim-1 complex reveals a new binding mode that may be general for Ser/Thr kinases.
Collapse
Affiliation(s)
- Marc D Jacobs
- Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts 02139, USA.
| | | | | | | | | | | | | |
Collapse
|
49
|
Zachos G, Rainey MD, Gillespie DAF. Chk1-dependent S-M checkpoint delay in vertebrate cells is linked to maintenance of viable replication structures. Mol Cell Biol 2005; 25:563-74. [PMID: 15632059 PMCID: PMC543419 DOI: 10.1128/mcb.25.2.563-574.2005] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [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: 01/06/2023] Open
Abstract
We investigated mitotic delay during replication arrest (the S-M checkpoint) in DT40 B-lymphoma cells deficient in the Chk1 or Chk2 kinase. We show here that cells lacking Chk1, but not those lacking Chk2, enter mitosis with incompletely replicated DNA when DNA synthesis is blocked, but only after an initial delay. This initial delay persists when S-M checkpoint failure is induced in Chk2-/- cells with the Chk1 inhibitor UCN-01, indicating that it does not depend on Chk1 or Chk2 activity. Surprisingly, dephosphorylation of tyrosine 15 did not accompany Cdc2 activation during premature entry to mitosis in Chk1-/- cells, although mitotic phosphorylation of cyclin B2 did occur. Previous studies have shown that Chk1 is required to stabilize stalled replication forks during replication arrest, and strikingly, premature mitosis occurs only in Chk1-deficient cells which have lost the capacity to synthesize DNA as a result of progressive replication fork inactivation. These results suggest that Chk1 maintains the S-M checkpoint indirectly by preserving the viability of replication structures and that it is the continued presence of such structures, rather than the activation of Chk1 per se, which delays mitosis until DNA replication is complete.
Collapse
Affiliation(s)
- George Zachos
- Beatson Institute for Cancer Research, Garscube Estate, Switchback Rd., Glasgow G61 1BD, United Kingdom
| | | | | |
Collapse
|
50
|
Dai Y, Rahmani M, Pei XY, Khanna P, Han SI, Mitchell C, Dent P, Grant S. Farnesyltransferase inhibitors interact synergistically with the Chk1 inhibitor UCN-01 to induce apoptosis in human leukemia cells through interruption of both Akt and MEK/ERK pathways and activation of SEK1/JNK. Blood 2005; 105:1706-16. [PMID: 15494423 DOI: 10.1182/blood-2004-07-2767] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [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: 02/05/2023] Open
Abstract
Abstract
Interactions between the Chk1 inhibitor UCN-01 and the farnesyltransferase inhibitor L744832 were examined in human leukemia cells. Combined exposure of U937 cells to subtoxic concentrations of UCN-01 and L744832 resulted in a dramatic increase in mitochondrial dysfunction, apoptosis, and loss of clonogenicity. Similar interactions were noted in other leukemia cells (HL-60, Raji, Jurkat) and primary acute myeloid leukemia (AML) blasts. Coadministration of L744832 blocked UCN-01-mediated phosphorylation of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK), leading to down-regulation of phospho-cyclic adenosine monophosphate responsive element-binding protein (phospho-CREB) and -p90RSK and activation of p34cdc2 and stress-activated protein kinase/ERK kinase/c-Jun N-terminal kinase (SEK/JNK). Combined treatment also resulted in pronounced reductions in levels of phospho-Akt, -glycogen synthase kinase-3 (-GSK-3), -p70S6K, -mammalian target of rapamycin (-mTOR), -forkhead transcription factor (-FKHR), -caspase-9, and -Bad. Ectopic expression of Bcl-2 or Bcl-xL but not dominant-negative caspase-8 blocked UCN-01/L744832-mediated mitochondrial dysfunction and apoptosis but did not prevent activation of p34cdc2 and JNK or inactivation of MEK/ERK and Akt. Enforced expression of myristoylated Akt but not constitutively active MEK significantly attenuated UCN-01/L744832-induced apoptosis. However, dual transfection with Akt and MEK resulted in further protection from UCN-01/L744832-mediated lethality. Finally, down-regulation of JNK1 by siRNA significantly reduced the lethality of the UCN-01/L744832 regimen. Together, these findings suggest that farnesyltransferase inhibitors interrupt the cytoprotective Akt and MAPK pathways while reciprocally activating SAPK/JNK in leukemia cells exposed to UCN-01 and, in so doing, dramatically increase mitochondria-dependent apoptosis. (Blood. 2005;105:1706-1716)
Collapse
Affiliation(s)
- Yun Dai
- Department of Medicine, Virginia Commonwealth University/Medical College of Virginia, Richmond VA, 23298, USA
| | | | | | | | | | | | | | | |
Collapse
|