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Matthew Ball, Anne Baron, Ben Bradshaw, Raphaël Dumeunier, Matthew O'Brien, Eric J Thomas
The development of a synthesis of the C1-C16 fragment of bryostatins in which the key step is a stereoselective oxy-Michael reaction used to assemble the cis-2,6-disubstituted tetrahydropyran with the exocyclic alkene already installed, is described. Following early work using Stille reactions to prepare precursors for oxy-Michael reactions, a more efficient route was devised based on a ketophosphonate-aldehyde condensation to prepare the key dienone. Synthesis of the aldehyde required for the ketophosphonate condensation involved the highly stereoselective addition of a diorganocuprate derived from allylmagnesium bromide and copper(i) iodide to the methyl 5-hydroxyhex-2-ynoate prepared by ring-opening of a protected glycidol using lithiated methyl propiolate...
October 12, 2016: Organic & Biomolecular Chemistry
Mark E Petersen, Noemi Kedei, Nancy E Lewin, Peter M Blumberg, Gary E Keck
We describe a convergent synthesis of a bryostatin analogue in which the natural A- and B-ring pyrans have been replaced by phenyl rings. The new analogue exhibited PMA like behavior in cell assays, but failed to maintain high affinity binding for PKC, despite retaining an unaltered C-ring 'binding domain'.
October 19, 2016: Tetrahedron Letters
John M Ketcham, Ivan Volchkov, Te-Yu Chen, Peter M Blumberg, Noemi Kedei, Nancy E Lewin, Michael J Krische
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...
October 12, 2016: Journal of the American Chemical Society
Rana Abdelnabi, Daryl Staveness, Katherine E Near, Paul A Wender, Leen Delang, Johan Neyts, Pieter Leyssen
Previously, we reported that salicylate-based analogs of bryostatin protect cells from chikungunya virus (CHIKV)-induced cell death. Interestingly, 'capping' the hydroxyl group at C26 of a lead bryostatin analog, a position known to be crucial for binding to and modulation of protein kinase C (PKC), did not abrogate the anti-CHIKV activity of the scaffold, putatively indicating the involvement of a pathway independent of PKC. The work detailed in this study demonstrates that salicylate-derived analog 1 and two capped analogs (2 and 3) are not merely cytoprotective compounds, but act as selective and specific inhibitors of CHIKV replication...
September 21, 2016: Biochemical Pharmacology
Ian J Miller, Niti Vanee, Stephen S Fong, Grace E Lim-Fong, Jason C Kwan
: The uncultured bacterial symbiont "Candidatus Endobugula sertula" is known to produce cytotoxic compounds called bryostatins, which protect the larvae of its host, Bugula neritina The symbiont has never been successfully cultured and it was thought that its genome might be significantly reduced. Here, we took a shotgun metagenomics and metatranscriptomics approach to assemble and characterize the genome of "Ca. E. sertula". We found that it had specific metabolic deficiencies in the biosynthesis of certain amino acids, but few other signs of genome degradation such as small size, abundant pseudogenes or low coding density...
September 2, 2016: Applied and Environmental Microbiology
Amy E Baxter, Julia Niessl, Rémi Fromentin, Jonathan Richard, Filippos Porichis, Roxanne Charlebois, Marta Massanella, Nathalie Brassard, Nirmin Alsahafi, Gloria-Gabrielle Delgado, Jean-Pierre Routy, Bruce D Walker, Andrés Finzi, Nicolas Chomont, Daniel E Kaufmann
HIV cure efforts are hampered by limited characterization of the cells supporting HIV replication in vivo and inadequate methods for quantifying the latent viral reservoir in patients receiving antiretroviral therapy. We combine fluorescent in situ RNA hybridization with detection of HIV protein and flow cytometry, enabling detection of 0.5-1 gag-pol mRNA(+)/Gag protein(+)-infected cells per million. In the peripheral blood of untreated persons, active HIV replication correlated with viremia and occurred in CD4 T cells expressing T follicular helper cell markers and inhibitory co-receptors...
September 14, 2016: Cell Host & Microbe
David O Baumann, Kevin M McGowan, Noemi Kedei, Megan L Peach, Peter M Blumberg, Gary E Keck
As an initial step in designing a simplified bryostatin hybrid molecule, three bryostatin analogues bearing a diacylglycerol lactone-based C-ring, which possessed the requisite pharmacophores for binding to protein kinase C (PKC) together with a modified bryostatin-like A- and B-ring region, were synthesized and evaluated. Merle 46 and Merle 47 exhibited binding affinity to PKC alpha with Ki values of 7000 ± 990 and 4940 ± 470 nM, respectively. Reinstallation of the trans-olefin and gem-dimethyl group present in bryostatin 1 in Merle 48 resulted in improved binding affinity, 363 ± 42 nM...
September 2, 2016: Journal of Organic Chemistry
Nicoletta Marchesi, Marialaura Amadio, Claudia Colombrita, Stefano Govoni, Antonia Ratti, Alessia Pascale
Neuronal ELAV/Hu (nELAV) are RNA-binding proteins that mainly regulate gene expression by increasing the stability and/or translation rate of target mRNAs bearing ARE (adenine and uracil-rich elements) sequences. Among nELAV target transcripts there is ADAM10, an α-secretase involved in the non-amyloidogenic processing of the amyloid-β protein precursor (AβPP) which leads to the production of the neuroprotective sAβPPα peptide. The aim of this study was to evaluate if nELAV depletion affects ADAM10 expression in human SH-SY5Y neuroblastoma cells...
September 6, 2016: Journal of Alzheimer's Disease: JAD
Victoria E Walker-Sperling, Christopher W Pohlmeyer, Patrick M Tarwater, Joel N Blankson
Shock and kill strategies involving the use of small molecules to induce viral transcription in resting CD4+ T cells (shock) followed by immune mediated clearance of the reactivated cells (kill), have been proposed as a method of eliminating latently infected CD4+ T cells. The combination of the histone deacetylase (HDAC) inhibitor romidepsin and protein kinase C (PKC) agonist bryostatin-1 is very effective at reversing latency in vitro. However, we found that primary HIV-1 specific CD8+ T cells were not able to eliminate autologous resting CD4+ T cells that had been reactivated with these drugs...
June 2016: EBioMedicine
Jahahreeh Finley
In all mammalian species studied to date, the initiation of oocyte activation is orchestrated through alterations in intracellular calcium (Ca(2+)) signaling. Upon sperm binding to the oocyte plasma membrane, a sperm-associated phospholipase C (PLC) isoform, PLC zeta (PLCζ), is released into the oocyte cytoplasm. PLCζ hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) to produce diacylglycerol (DAG), which activates protein kinase C (PKC), and inositol 1,4,5-trisphosphate (IP3), which induces the release of Ca(2+) from endoplasmic reticulum (ER) Ca(2+) stores...
August 2016: Medical Hypotheses
Abhik Sen, Jarin Hongpaisan, Desheng Wang, Thomas J Nelson, Daniel L Alkon
Protein kinase Cϵ (PKCϵ) promotes synaptic maturation and synaptogenesis via activation of synaptic growth factors such as BDNF, NGF, and IGF. However, many of the detailed mechanisms by which PKCϵ induces synaptogenesis are not fully understood. Accumulation of PSD-95 to the postsynaptic density (PSD) is known to lead to synaptic maturation and strengthening of excitatory synapses. Here we investigated the relationship between PKCϵ and PSD-95. We show that the PKCϵ activators dicyclopropanated linoleic acid methyl ester and bryostatin 1 induce phosphorylation of PSD-95 at the serine 295 residue, increase the levels of PSD-95, and enhance its membrane localization...
August 5, 2016: Journal of Biological Chemistry
Kenmei Mizutani, Shigeru Sonoda, Hideaki Wakita, Hideto Okazaki, Yoshimitsu Katoh, Takeshi Chihara, Kan Shimpo
Although it has been suggested that the combination of exercise and bryostatin-1 administration may induce greater functional recovery than exercise alone, the detailed molecular mechanisms are not well known. Here, we examined the relationship between this combination treatment and monoamine dynamics in the cerebral cortex peri-infarction area to promote our understanding of these molecular mechanisms. Experimental cerebral cortex infarctions were produced by photothrombosis in rats. Voluntary exercise was initiated 2 days after surgery...
June 15, 2016: Neuroreport
Sydney Plummer, Thomas Manning, Tess Baker, Tysheon McGreggor, Mehulkumar Patel, Greg Wylie, Dennis Phillips
Bryostatin-1 is a marine natural product that has demonstrated medicinal activity in pre-clinical and clinical trials for the treatment of cancer, Alzheimer's disease, effects of stroke, and HIV. In this study, iron-bryostatin-1 was obtained using a pharmaceutical aquaculture technique developed by our lab that cultivates marine bacteria for marine natural product extraction. Analytical measurements (1)H and (13)C NMR, mass spectrometry, and flame atomic absorption were utilized to confirm the presence of an iron-bryostatin-1 complex...
May 15, 2016: Bioorganic & Medicinal Chemistry Letters
Zhuo Li, Chuanyou Zhang, Li Chen, Guosheng Li, Ling Qu, K C Balaji, Cheng Du
Protein kinase D 1 (PKD1) is a serine/threonine kinase implicated in the regulation of diverse cellular functions including cell growth, differentiation, adhesion and motility. The current model for PKD1 activation involves diacylglycerol (DAG) binding to the C1 domain of PKD1 which results in the translocation of PKD1 to subcellular membranes where PKD1 is phosphorylated and activated by protein kinase C (PKC). In this study, we have identified a novel regulation of PKD1 activation. The epithelial cell membrane protein E-cadherin physically binds to PKD1 which leads to a subcellular redistribution of PKD1...
December 2016: Journal of Cellular Physiology
Miao-Kun Sun, Jarin Hongpaisan, Daniel L Alkon
Fragile X syndrome (FXS) is characterized by synaptic immaturity, cognitive impairment, and behavioral changes. The disorder is caused by transcriptional shutdown in neurons of thefragile X mental retardation 1gene product, fragile X mental retardation protein. Fragile X mental retardation protein is a repressor of dendritic mRNA translation and its silencing leads to dysregulation of synaptically driven protein synthesis and impairments of intellect, cognition, and behavior, and FXS is a disorder that currently has no effective therapeutics...
May 2016: Journal of Pharmacology and Experimental Therapeutics
Daryl Staveness, Rana Abdelnabi, Katherine E Near, Yu Nakagawa, Johan Neyts, Leen Delang, Pieter Leyssen, Paul A Wender
Chikungunya virus (CHIKV) has been spreading rapidly, with over one million confirmed or suspected cases in the Americas since late 2013. Infection with CHIKV causes devastating arthritic and arthralgic symptoms. Currently, there is no therapy to treat this disease, and the only medications focus on relief of symptoms. Recently, protein kinase C (PKC) modulators have been reported to inhibit CHIKV-induced cell death in cell assays. The salicylate-derived bryostatin analogues described here are structurally simplified PKC modulators that are more synthetically accessible than the natural product bryostatin 1, a PKC modulator and clinical lead for the treatment of cancer, Alzheimer's disease, and HIV eradication...
April 22, 2016: Journal of Natural Products
Daryl Staveness, Rana Abdelnabi, Adam J Schrier, Brian A Loy, Vishal A Verma, Brian A DeChristopher, Katherine E Near, Johan Neyts, Leen Delang, Pieter Leyssen, Paul A Wender
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus showing a recent resurgence and rapid spread worldwide. While vaccines are under development, there are currently no therapies to treat this disease, except for over-the-counter (OTC) analgesics, which alleviate the devastating arthritic and arthralgic symptoms. To identify novel inhibitors of the virus, analogues of the natural product bryostatin 1, a clinical lead for the treatment of cancer, Alzheimer's disease, and HIV eradication, were investigated for in vitro antiviral activity and were found to be among the most potent inhibitors of CHIKV replication reported to date...
April 22, 2016: Journal of Natural Products
Carolina Gutiérrez, Sergio Serrano-Villar, Nadia Madrid-Elena, Maria J Pérez-Elías, Maria Elena Martín, Coral Barbas, Javier Ruipérez, Eduardo Muñoz, Maria Angeles Muñoz-Fernández, Trevor Castor, Santiago Moreno
OBJECTIVE: The protein kinase C (PKC) agonist bryostatin-1 has shown significant ex-vivo potency to revert HIV-1 latency, compared with other latency reversing agents (LRA). The safety of this candidate LRA remains to be proven in treated HIV-1-infected patients. METHODS: In this pilot, double-blind phase I clinical-trial (NCT 02269605), we included aviraemic HIV-1-infected patients on triple antiretroviral therapy to evaluate the effects of two different single doses of bryostatin-1 (10 or 20 μg/m) compared with placebo...
June 1, 2016: AIDS
Jessica S Kelsey, Christophe Cataisson, Jinqiu Chen, Michelle A Herrmann, Mark E Petersen, David A Baumann, Kevin M McGowan, Stuart H Yuspa, Gary E Keck, Peter M Blumberg
Bryostatin 1, a complex macrocyclic lactone, is the subject of multiple clinical trials for cancer chemotherapy. Although bryostatin 1 biochemically functions like the classic mouse skin tumor promoter phorbol 12-myristate 13-acetate (PMA) to bind to and activate protein kinase C, paradoxically, it fails to induce many of the typical phorbol ester responses, including tumor promotion. Intense synthetic efforts are currently underway to develop simplified bryostatin analogs that preserve the critical functional features of bryostatin 1, including its lack of tumor promoting activity...
February 9, 2016: Molecular Carcinogenesis
Hongmei Li, Hui He, Leyi Gong, Mingui Fu, Tony T Wang
We report that the addition of an host paracaspase MALT1 inhibitor, MI-2, to HIV latently infected ACH-2, Jurkat E4, and J-LAT cells accelerated cell death in the presence of cell stimuli or the protein kinase C agonist, bryostatin 1. MI-2-mediated cell death correlated with the induction of the cellular RNase MCPIP1 and requires the presence of viral component(s). Altogether, the combination of MI-2 and bryostatin 1 displays selective killing of HIV latently infected CD4(+) T cells.
February 2016: AIDS Research and Human Retroviruses
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