1
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Targeting PKC in microglia to promote remyelination and repair in the CNS. Curr Opin Pharmacol 2021; 62:103-108. [PMID: 34965482 DOI: 10.1016/j.coph.2021.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/19/2021] [Indexed: 01/28/2023]
Abstract
Microglia and CNS-infiltrating macrophages play significant roles in the pathogenesis of neuroinflammatory and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Prolonged and dysregulated inflammatory responses by these innate immune cells can have deleterious effects on the surrounding CNS microenvironment, which can worsen neurodegeneration and demyelination. However, although chronic activation of pro-inflammatory microglia is maladaptive, other functional microglial subtypes play beneficial roles during CNS repair and regeneration. Therefore, there is a tremendous interest in understanding the underlying mechanism of the activation of these reparative/regenerative microglia. In this review, we focus on the potential role of PKC, a downstream signaling molecule of TREM2 and PLCγ2, and PKC modulators in promoting the activation of reparative/regenerative microglial subtypes as a novel therapy for neuroinflammatory and neurodegenerative diseases.
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2
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Benner NL, Near KE, Bachmann MH, Contag CH, Waymouth RM, Wender PA. Functional DNA Delivery Enabled by Lipid-Modified Charge-Altering Releasable Transporters (CARTs). Biomacromolecules 2018; 19:2812-2824. [PMID: 29727572 PMCID: PMC6542359 DOI: 10.1021/acs.biomac.8b00401] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Safe and effective DNA delivery systems are required to enable or enhance clinical strategies and research involving gene therapy and DNA vaccinations. To address this delivery problem, a series of charge-altering releasable transporters (CARTs) with varied lipid content were prepared and evaluated for plasmid DNA (pDNA) delivery into cultured cells. These lipid-modified CART co-oligomers were synthesized in only two steps via sequential organocatalytic ring-opening polymerization of lipid-containing cyclic carbonate monomers and morpholinone monomers. Lipid variations of the CARTs substantially impacted the delivery efficiency of pDNA, with oleyl- and linoleyl-based CARTs showing enhanced performance relative to the commercial transfection agent Lipofectamine 2000 (L2000). The best-performing oleyl CART was carried forward to study stable luciferase transfection with a Sleeping Beauty ( SB) transposon system. The oleyl CART outperformed the L2000 positive control with respect to stable transfection efficiency. CART-pDNA complexes represent a new DNA delivery system for research and clinical applications.
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Affiliation(s)
- Nancy L. Benner
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Katherine E. Near
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Michael H. Bachmann
- Department of Pediatrics, Stanford University, Stanford, California 94305, United States
| | - Christopher H. Contag
- Department of Pediatrics, Stanford University, Stanford, California 94305, United States
- Department of Microbiology and Immunology, Stanford University, Stanford, California 94305, United States
- Department of Radiology, Stanford University, Stanford, California 94305, United States
| | - Robert M. Waymouth
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Paul A. Wender
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
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3
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Ketcham JM, Volchkov I, Chen TY, Blumberg PM, Kedei N, Lewin NE, Krische MJ. Evaluation of Chromane-Based Bryostatin Analogues Prepared via Hydrogen-Mediated C-C Bond Formation: Potency Does Not Confer Bryostatin-like Biology. J Am Chem Soc 2016; 138:13415-13423. [PMID: 27676096 PMCID: PMC5094189 DOI: 10.1021/jacs.6b08695] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis and biological evaluation of chromane-containing bryostatin analogues WN-2-WN-7 and the previously reported salicylate-based analogue WN-8 are described. Analogues WN-2-WN-7 are prepared through convergent assembly of the chromane-containing fragment B-I with the "binding domain" fragment A-I or its C26-des-methyl congener, fragment A-II. The synthesis of fragment B-I features enantioselective double C-H allylation of 1,3-propanediol to form the C2-symmetric diol 3 and Heck cyclization of bromo-diene 5 to form the chromane core. The synthesis of salicylate WN-8 is accomplished through the union of fragments A-III and B-II. The highest binding affinities for PKCα are observed for the C26-des-methyl analogues WN-3 (Ki = 63.9 nM) and WN-7 (Ki = 63.1 nM). All analogues, WN-2-WN-8, inhibited growth of Toledo cells, with the most potent analogue being WN-7. This response, however, does not distinguish between phorbol ester-like and bryostatin-like behavior. In contrast, while many of the analogues contain a conserved C-ring in the binding domain and other features common to analogues with bryostatin-like properties, all analogues evaluated in the U937 proliferation and cell attachment assays displayed phorbol ester-like and/or toxic behavior, including WN-8, for which "bryostatin-like PKC modulatory activities" previously was suggested solely on the basis of PKC binding. These results underscore the importance of considering downstream biological effects, as tumor suppression cannot be inferred from potent PKC binding.
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Affiliation(s)
- John M. Ketcham
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Ivan Volchkov
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Te-Yu Chen
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
| | - Peter M. Blumberg
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Nancy E. Lewin
- Laboratory of Cancer Biology and Genetics, NCI, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Michael J. Krische
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX 78712, USA
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4
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Andrews IP, Ketcham JM, Blumberg PM, Kedei N, Lewin N, Peach ML, Krische MJ. Synthesis of seco-B-ring bryostatin analogue WN-1 via C-C bond-forming hydrogenation: critical contribution of the B-ring in determining bryostatin-like and phorbol 12-myristate 13-acetate-like properties. J Am Chem Soc 2014; 136:13209-16. [PMID: 25207655 PMCID: PMC4183601 DOI: 10.1021/ja507825s] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Indexed: 01/31/2023]
Abstract
The seco-B-ring bryostatin analogue, macrodiolide WN-1, was prepared in 17 steps (longest linear sequence) and 30 total steps with three bonds formed via hydrogen-mediated C-C coupling. This synthetic route features a palladium-catalyzed alkoxycarbonylation of a C2-symmetric diol to form the C9-deoxygenated bryostatin A-ring. WN-1 binds to PKCα (Ki = 16.1 nM) and inhibits the growth of multiple leukemia cell lines. Although structural features of the WN-1 A-ring and C-ring are shared by analogues that display bryostatin-like behavior, WN-1 displays PMA-like behavior in U937 cell attachment and proliferation assays, as well as in K562 and MV-4-11 proliferation assays. Molecular modeling studies suggest the pattern of internal hydrogen bonds evident in bryostatin 1 is preserved in WN-1, and that upon docking WN-1 into the crystal structure of the C1b domain of PKCδ, the binding mode of bryostatin 1 is reproduced. The collective data emphasize the critical contribution of the B-ring to the function of the upper portion of the molecule in conferring a bryostatin-like pattern of biological activity.
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Affiliation(s)
- Ian P. Andrews
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
| | - John M. Ketcham
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
| | - Peter M. Blumberg
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Noemi Kedei
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Nancy
E. Lewin
- Laboratory
of Cancer Biology and Genetics, National
Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, United States
| | - Megan L. Peach
- Basic Science Program,
Leidos Biomedical Research, Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Michael J. Krische
- Department
of Chemistry and Biochemistry, University
of Texas at Austin, Austin, Texas 78712, United States
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5
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Wender PA, Reuber J. Function Oriented Synthesis: Preparation and Initial Biological Evaluation of New A-Ring-Modified Bryologs. Tetrahedron 2011; 67:9998-10005. [PMID: 22247574 DOI: 10.1016/j.tet.2011.09.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The synthesis and biological evaluation of the first members of a new series of designed bryostatin A-ring analogues (bryologs) are described. An advanced intermediate is produced that allows for step economical access to diverse analogs. The first of these analogues, bearing side chains of completely different polarities from alkyl to hydroxyl and carboxyl functionalities, were evaluated. All exhibit potent protein kinase C binding (54.7 to 2.4 nM) with affinities increasing with decreasing side chain polarity. This series of bryostatin analogues demonstrates that A ring surrogates can indeed be used for tuning pharmacophore and ADME characteristics as needed to improve bryolog function.
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Affiliation(s)
- Paul A Wender
- Department of Chemistry, Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305-5080, USA
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6
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Smith AB, Risatti CA, Atasoylu O, Bennett CS, Liu J, Cheng H, TenDyke K, Xu Q. Design, synthesis, and biological evaluation of diminutive forms of (+)-spongistatin 1: lessons learned. J Am Chem Soc 2011; 133:14042-53. [PMID: 21761891 PMCID: PMC3164888 DOI: 10.1021/ja2046167] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The design, synthesis, and biological evaluation of two diminutive forms of (+)-spongistatin 1, in conjunction with the development of a potentially general design strategy to simplify highly flexible macrocyclic molecules while maintaining biological activity, have been achieved. Examination of the solution conformations of (+)-spongistatin 1 revealed a common conformational preference along the western perimeter comprising the ABEF rings. Exploiting the hypothesis that the small-molecule recognition/binding domains are likely to comprise the conformationally less mobile portions of a ligand led to the design of analogues, incorporating tethers (blue) in place of the CD and the ABCD components of the (+)-spongistatin 1 macrolide, such that the conformation of the retained (+)-spongistatin 1 skeleton would mimic the assigned solution conformations of the natural product. The observed nanomolar cytotoxicity and microtubule destabilizing activity of the ABEF analogue provide support for both the assigned solution conformation of (+)-spongistatin 1 and the validity of the design strategy.
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Affiliation(s)
- Amos B Smith
- Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, Department of Chemistry, University of Pennsylvania , Philadelphia, 19104, United States.
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7
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Wender PA, Loy BA, Schrier AJ. Translating Nature's Library: The Bryostatins and Function-Oriented Synthesis. Isr J Chem 2011; 51:453-472. [PMID: 22661768 PMCID: PMC3364006 DOI: 10.1002/ijch.201100020] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We review in part our computational, design, synthesis, and biological studies on a remarkable class of compounds and their designed analogs that have led to preclinical candidates for the treatment of cancer, a first-in-class approach to Alzheimer's disease, and a promising strategy to eradicate HIV/AIDS. Because these leads target, in part, protein kinase C (PKC) isozymes, they have therapeutic potential even beyond this striking set of therapeutic indications. This program has given rise to new synthetic methodology and represents an increasingly important direction of synthesis focused on achieving function through synthesis-informed design (function-oriented synthesis).
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Affiliation(s)
- Paul A. Wender
- Department of Chemistry Department of Chemical and Systems Biology Stanford University Stanford, CA 94305, USA
| | - Brian A. Loy
- Department of Chemistry Department of Chemical and Systems Biology Stanford University Stanford, CA 94305, USA
| | - Adam J. Schrier
- Department of Chemistry Department of Chemical and Systems Biology Stanford University Stanford, CA 94305, USA
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8
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Design, synthesis, and evaluation of potent bryostatin analogs that modulate PKC translocation selectivity. Proc Natl Acad Sci U S A 2011; 108:6721-6. [PMID: 21415363 DOI: 10.1073/pnas.1015270108] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Modern methods for the identification of therapeutic leads include chemical or virtual screening of compound libraries. Nature's library represents a vast and diverse source of leads, often exhibiting exquisite biological activities. However, the advancement of natural product leads into the clinic is often impeded by their scarcity, complexity, and nonoptimal properties or efficacy as well as the challenges associated with their synthesis or modification. Function-oriented synthesis represents a strategy to address these issues through the design of simpler and therefore synthetically more accessible analogs that incorporate the activity-determining features of the natural product leads. This study illustrates the application of this strategy to the design and synthesis of functional analogs of the bryostatin marine natural products. It is specifically directed at exploring the activity-determining role of bryostatin A-ring functionality on PKC affinity and selectivity. The resultant functional analogs, which were prepared by a flexible, modular synthetic strategy, exhibit excellent affinity to PKC and differential isoform selectivity. These and related studies provide the basic information needed for the design of simplified and thus synthetically more accessible functional analogs that target PKC isoforms, major targets of therapeutic interest.
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9
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Lee KB, Hwang JM, Choi IS, Rho J, Choi JS, Kim GH, Kim SI, Kim S, Lee ZW. Direct Monitoring of the Inhibition of Protein-Protein Interactions in Cells by Translocation of PKCδ Fusion Proteins. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201005333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Lee KB, Hwang JM, Choi IS, Rho J, Choi JS, Kim GH, Kim SI, Kim S, Lee ZW. Direct Monitoring of the Inhibition of Protein-Protein Interactions in Cells by Translocation of PKCδ Fusion Proteins. Angew Chem Int Ed Engl 2011; 50:1314-7. [DOI: 10.1002/anie.201005333] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Indexed: 11/09/2022]
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11
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Szpilman AM, Carreira EM. Probing the Biology of Natural Products: Molecular Editing by Diverted Total Synthesis. Angew Chem Int Ed Engl 2010; 49:9592-628. [DOI: 10.1002/anie.200904761] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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12
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Szpilman AM, Carreira EM. Untersuchung der Biologie von Naturstoffen: systematische Strukturvariation durch umgelenkte Totalsynthese. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200904761] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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13
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Hale KJ, Manaviazar S. New approaches to the total synthesis of the bryostatin antitumor macrolides. Chem Asian J 2010; 5:704-54. [PMID: 20354984 DOI: 10.1002/asia.200900634] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In this Focus Review, we give an overview of various bryostatin total syntheses. We also discuss the synthesis of various bryostatin analogues and their biological activity. Work reviewed includes that of Masamune, Evans, Nishiyama and Yamamura, Hale and Manaviazar, Trost, Wender, Keck, Burke, Thomas, and Krische. Our coverage is primarily for the period 2001-2009, since detailed reviews already exist on bryostatin total synthesis work and biology up to this time.
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Affiliation(s)
- Karl J Hale
- School of Chemistry & Chemical Engineering, Queen's Universty Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK.
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14
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Bedoya LM, Márquez N, Martínez N, Gutiérrez-Eisman S, Álvarez A, Calzado MA, Rojas JM, Appendino G, Muñoz E, Alcamí J. SJ23B, a jatrophane diterpene activates classical PKCs and displays strong activity against HIV in vitro. Biochem Pharmacol 2009; 77:965-78. [DOI: 10.1016/j.bcp.2008.11.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 11/24/2008] [Accepted: 11/25/2008] [Indexed: 10/21/2022]
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15
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Singh SB, Pelaez F. Biodiversity, chemical diversity and drug discovery. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2007; 65:141, 143-74. [PMID: 18084915 DOI: 10.1007/978-3-7643-8117-2_4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Drugs developed from microbial natural products are in the fundaments of modern pharmaceutical companies. Despite decades of research, all evidences suggest that there must remain many interesting natural molecules with potential therapeutic application yet to be discovered. Any efforts to successfully exploit the chemical diversity of microbial secondary metabolites need to rely heavily on a good understanding of microbial diversity, being the working hypothesis that maximizing biological diversity is the key strategy to maximizing chemical diversity. This chapter presents an overview of diverse topics related with this basic principle, always in relation with the discovery of novel secondary metabolites. The types of microorganisms more frequently used for natural products discovery are briefly reviewed, as well as the differences between terrestrial and marine habitats as sources of bioactive secondary metabolite producers. The concepts about microbial diversity as applied to prokaryotes have evolved in the last years, but recent data suggest the existence of true biogeographic patterns of bacterial diversity, which are also discussed. Special attention is dedicated to the existing strategies to exploit the microbial diversity that is not easy to tackle by conventional approaches. This refers explicitly to the current attempts to isolate and cultivate the previously uncultured bacteria, including the application of high throughput techniques. Likewise, the advances of microbial molecular biology has allowed the development of metagenomic approaches, i.e., the expression of biosynthetic pathways directly obtained from environmental DNA and cloned in a suitable host, as another way of accessing microbial genetic resources. Also, approaches relying on the genomics of metabolite producers are reviewed.
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Affiliation(s)
- Sheo B Singh
- Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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16
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Abstract
Gliomas are the most common major subgroup of primary CNS tumours. Approximately 17,000 new cases are reported each year and, of these, 11,500 patients die. Glioblastoma multiforme (GBM) is highly proliferative and typically invades distal portions of the brain, thereby making complete surgical resection of these tumours nearly impossible. Moreover, GBMs are often resistant to current chemotherapy and radiation regimens. Therefore, there is a need for better therapeutic interventions. One class of proteins that is involved in the formation of malignant brain tumours is protein kinase C (PKC) and these kinases have not been thoroughly explored for their chemotherapeutic value in GBMs. The PKC isozyme, PKCeta (PKC-eta) increases cell proliferation and resistance to radiation of GBM cell lines. These properties make PKCeta an attractive target for chemotherapeutic intervention in the management of GBMs.
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Affiliation(s)
- Patrick M Martin
- Department of Pathology, University of Virginia, Charlottesville, VA, USA.
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17
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Wender PA, Verma VA. Design, Synthesis, and Biological Evaluation of a Potent, PKC Selective, B-Ring Analog of Bryostatin. Org Lett 2006; 8:1893-6. [PMID: 16623578 DOI: 10.1021/ol060457z] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
[structure: see text] The first member of a new class of five-membered B-ring analogs of bryostatin has been synthesized and tested for its ability to bind and translocate protein kinase C (PKC). This synthesis extends the utility of our previously introduced macrotransacetalization strategy to the formation of five-membered dioxolane B-ring analogs. This analog exhibits potent, single-digit nanomolar affinity to PKC and selectively translocates novel PKC isozymes.
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Affiliation(s)
- Paul A Wender
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
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18
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Tomic J, White D, Shi Y, Mena J, Hammond C, He L, Miller RL, Spaner DE. Sensitization of IL-2 Signaling through TLR-7 Enhances B Lymphoma Cell Immunogenicity. THE JOURNAL OF IMMUNOLOGY 2006; 176:3830-9. [PMID: 16517754 DOI: 10.4049/jimmunol.176.6.3830] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The innate ability of B lymphoma cells to escape control by tumor-reactive T cells must be overcome to develop effective immunotherapies for these diseases. Because signals from both the innate and adaptive immune systems direct the acquisition of strong immunogenicity by professional APCs, the effects of IL-2 and the TLR-7 agonist, S28690, on the immunogenic properties of chronic lymphocytic leukemia (CLL) B cells were studied. IL-2 with S28690 caused CLL cells to proliferate and increased their expression of B7-family members, production of TNF-alpha and IL-10, and levels of tyrosine-phosphorylated STAT-1 and STAT-3 proteins. S28690 increased CD25 expression on CLL cells and sensitized them to IL-2 signaling. However, IL-2 did not change TLR-7 expression or signaling in CLL cells. The ability to stimulate T cell proliferation required additional activation of protein kinase C, which inhibited tumor cell proliferation, "switched off" IL-10 production, and caused essentially all CLL cells (regardless of clinical stage) to acquire a CD83(high)CD80(high)CD86(high)CD54(high) surface phenotype marked by the activation of STAT-1 without STAT-3. These findings suggest that TLR-7 "licenses" human B cells to respond to cytokines of the adaptive immune system (such as IL-2) and provide a strategy to increase the immunogenicity of lymphoma cells for therapeutic purposes.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Cells, Cultured
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Imidazoles/pharmacology
- Interleukin-2/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/metabolism
- Lymphoma, B-Cell/pathology
- Male
- Middle Aged
- Phenotype
- Protein Kinase C/metabolism
- Quinolines/pharmacology
- Receptors, Interleukin-2/genetics
- STAT1 Transcription Factor/metabolism
- STAT3 Transcription Factor/metabolism
- Signal Transduction
- Toll-Like Receptor 7/immunology
- Toll-Like Receptor 7/metabolism
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Affiliation(s)
- Jelena Tomic
- Division of Molecular and Cellular Biology, Research Institute, Sunnybrook and Women's College Health Sciences Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
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19
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Statsuk AV, Bai R, Baryza JL, Verma VA, Hamel E, Wender PA, Kozmin SA. Actin is the primary cellular receptor of bistramide A. Nat Chem Biol 2006; 1:383-8. [PMID: 16372404 DOI: 10.1038/nchembio748] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bistramide A (1) is a marine natural product with broad, potent antiproliferative effects. Bistramide A has been reported to selectively activate protein kinase C (PKC) delta, leading to the view that PKCdelta is the principal mediator of antiproliferative activity of this natural product. Contrary to this observation, we established that bistramide A binds PKCdelta with low affinity, does not activate this kinase in vitro and does not translocate GFP-PKCdelta. Furthermore, we identified actin as the cellular receptor of bistramide A. We report that bistramide A disrupts the actin cytoskeleton, inhibits actin polymerization, depolymerizes filamentous F-actin in vitro and binds directly to monomeric G-actin in a 1:1 ratio with a Kd of 7 nM. We also constructed a fully synthetic9 bistramide A-based affinity matrix and isolated actin as a specific bistramide A-binding protein. This activity provides a molecular explanation for the potent antiproliferative effects of bistramide A, identifying it as a new biochemical tool for studies of the actin cytoskeleton and as a potential lead for development of a new class of antitumor agents.
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Affiliation(s)
- Alexander V Statsuk
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, USA
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20
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Wender PA, Baryza JL. Identification of a tunable site in bryostatin analogs: C20 Bryologs through late stage diversification. Org Lett 2005; 7:1177-80. [PMID: 15760168 DOI: 10.1021/ol0501931] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text] The C20 region of our bryostatin analogs was identified as a nonpharmacophoric site that could be varied to tune analogs for function and physical properties without significantly affecting their binding affinity for PKC. The use of this site in a late-stage diversification strategy has enabled the facile synthesis of a variety of new C20 analogs, all of which retain nanomolar affinity for PKC, in agreement with our pharmacophore hypothesis.
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Affiliation(s)
- Paul A Wender
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
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21
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Alkon DL, Epstein H, Kuzirian A, Bennett MC, Nelson TJ. Protein synthesis required for long-term memory is induced by PKC activation on days before associative learning. Proc Natl Acad Sci U S A 2005; 102:16432-7. [PMID: 16258064 PMCID: PMC1283453 DOI: 10.1073/pnas.0508001102] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Indexed: 11/18/2022] Open
Abstract
Protein synthesis has long been known to be required for associative learning to consolidate into long-term memory. Here we demonstrate that PKC isozyme activation on days before training can induce the synthesis of proteins necessary and sufficient for subsequent long-term memory consolidation. Bryostatin (Bryo), a macrolide lactone with efficacy in subnanomolar concentrations and a potential therapeutic for Alzheimer's disease, is a potent activator of PKC, some of whose isozymes undergo prolonged activation after associative learning. Under normal conditions, two training events with paired visual and vestibular stimuli cause short-term memory of the mollusc Hermissenda that lasts approximately 7 min. However, after 4-h exposures to Bryo (0.25 ng/ml) on two preceding days, the same two training events produced long-term conditioning that lasted >1 week and that was not blocked by anisomycin (1 mug/ml). Anisomycin, however, eliminated long-term memory lasting at least 1 week after nine training events. Both the nine training events alone and two Bryo exposures plus two training event regimens caused comparably increased levels of the PKC alpha-isozyme substrate calexcitin in identified type B neurons and enhanced PKC activity in the membrane fractions. Furthermore, Bryo increased overall protein synthesis in cultured mammalian neurons by up to 60% for >3 days. The specific PKC antagonist Ro-32-0432 blocked much of this Bryo-induced protein synthesis as well as the Bryo-induced enhancement of the behavioral conditioning. Thus, Bryo-induced PKC activation produces those proteins necessary and sufficient for long-term memory on days in advance of the training events themselves.
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Affiliation(s)
- Daniel L Alkon
- Blanchette Rockefeller Neurosciences Institute, 9601 Medical Center Drive, Rockville, MD 20850-3332, USA.
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Wender PA, Clarke MO, Horan JC. Role of the A-Ring of Bryostatin Analogues in PKC Binding: Synthesis and Initial Biological Evaluation of New A-Ring-Modified Bryologs. Org Lett 2005; 7:1995-8. [PMID: 15876038 DOI: 10.1021/ol0504650] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The syntheses of three newly designed bryostatin analogues are reported. These simplified analogues, which lack the A-ring present in the natural product but possess differing groups at C9, were obtained using a divergent approach from a common intermediate. All three analogues exhibit potent, single-digit nanomolar affinity to protein kinase C.
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Affiliation(s)
- Paul A Wender
- Department of Chemistry, Stanford University, California 94305-5080, USA.
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