Design, Synthesis and Evaluation of Non-Canonical Hsp90 Modulators

Novobiocin, a known DNA gyrase inhibitor, binds to a nucleotide-binding site located on the Hsp90 C-terminus and induces degradation of Hsp90-dependent client proteins at ~700 &muM in breast cancer cells (SKBr3). Although many analogues of novobiocin have been synthesized in an attempt to improve upon this activity, it was only recently demonstrated that monomeric species can exhibit antiproliferative activity against various cancer cell lines. To further refine the essential elements of the coumarin core, a series of modified coumarin derivatives was synthesized and evaluated. Structure&ndashactivity relationships for novobiocin as an anti-cancer agent were elucidated through analogues that manifest low micromolar to nanomolar activity against several cancer cell lines. The compound that exhibited the best and most consistent activity has been further evaluated against a broader panel of cancers as well as taken into an in vivo model. Studies are ongoing to further refine the coumarin core, with the potential to replace it with a more suitable heterocyclic ring system. In addition to the coumarin portion, a noviose sugar and benzamide side chain are appended to the natural product. Because limited information exists regarding the role of the sugar appendage, a series of non-sugar derivatives was synthesized and evaluated to establish structure&ndashactivity relationships for the noviose region of novobiocin. These studies have produced simplified novobiocin analogues that manifest low micromolar activity against a panel of cancer cell lines. Likewise, studies have been executed to elucidate details concerning the benzamide side chain and its potential to make hydrophobic interactions with the binding pocket. The most promising compound from each of these series has demonstrated impressive activity against several cancer cell lines and have been evaluated in vivo. Efforts to understand the mechanism of action manifested by these diverse Hsp90 modulators are ongoing and have resulted in the existence of at least three distinct classes of Hsp90 C-terminal modulators. Moreover, collaborative studies with the NCI have revealed promising results with a compound that modulates Hsp90 through yet another disparate, but synergistic, mechanism. Through current studies, we hope to better solubilize the most potent compounds and advance novel Hsp90 modulators into clinical development

indicators for Ireland (2000-LS-5.2.2-M1) ; final report

The Third Assessment Report of the Intergovernmental Panel on Climate Change represented a consensus among the world's leading climate scientists that rapid climate changes were occurring on a global scale. In particular, the marked warming that had occurred over the past half century was, they concluded, substantially caused by the build-up of greenhouse gases in the troposphere as a result of anthropogenic activities. Globally, 1998 was the warmest year of the warmest decade of the warmest century of at least the last millennium. Such fluctuations, the IPCC suggested, were already capable of being associated with changes in a diverse set of physical and biological indicators in many parts of the world. Indicators of climate change are primarily used to simplify a complex reality and to communicate, more succinctly, critical information regarding climatic trends. They also provide an essential early warning system by making available information that may point to an environmental problem which is capable of being ameliorated before it becomes critical. In establishing indicators, a distinction can be made between primary indicators, based on analysis of directly observed meteorological data, and secondary indicators, based on the responses of the living world to climate changes which provoke a response in living organisms.researc

Exploring the lived experience of endoscopy trainees and their perceptions of nurse endoscopists as trainers

Background UK endoscopy services face considerable workforce pressures from an increasing demand for procedures. To meet this need, health services have introduced the role of nurse endoscopist (also known as clinical, non-medical or non-physician endoscopist). These roles have grown and developed to include performing many complex diagnostic and therapeutic procedures, as well as the provision of endoscopy training. Aims This study examines the lived experiences of (nurse and medical) endoscopy trainees, especially regarding being trained by nurse endoscopists. Methods The study employed interpretive phenomenological analysis (IPA). Data were collected through semi-structured in-depth interviews of 10 participants, who were selected from a sample of trainees attending a basic colonoscopy skills course. Interviews were preceded by observations to gain contextual insights into the training experience. The data were analysed in stages through a process of reading and re-reading the transcripts, making initial descriptive observations and then annotating with discursive, linguistic and conceptual comments. Findings Four emerging themes were identified. A lack self-confidence was a barrier to progression, compounded by the emotional impact of making mistakes without comprehensible constructive feedback. Attitudes of trainers and other endoscopy staff, as well as their relationships with trainees, had an impact on self-confidence and educational experience. Pressure on endoscopy units to perform procedures led to a tendency to treat training like a burden, although training was seen as an important investment. Trainees sought to differentiate nurse endoscopist and medical endoscopist roles and justify their skills and value, with comparisons between different nurse and medical trainers. Conclusion The emerging themes illustrate the requirement for a collegiate approach to endoscopy training

A novel C-terminal HSP90 inhibitor KU135 induces apoptosis and cell cycle arrest in melanoma cells

Heat shock protein 90 (Hsp90) is differentially expressed in tumor cells including melanoma and involved in proper folding, stabilization and regulation of cellular proteins. We investigated a novobiocin-derived Hsp90 C-terminal inhibitor, KU135, for anti-proliferative effects in melanoma cells. The results indicate that KU135 reduced cell viability and cell proliferation in melanoma cells and IC50 values for A735(DRO), M14(NPA), B16F10 and SKMEL28 cells were 0.82, 0.92, 1.33 and 1.30 M respectively. KU135 induced a more potent anti-proliferative effect in most melanoma cells versus N-terminal Hsp90 inhibitor 17AAG. KU135 induced apoptosis in melanoma cells, as indicated by annexin V/PI staining, reduction in the mitochondrial membrane potential, mitochondrial cytochrome C release and caspase 3 activation. KU135 reduced levels of Hsp90 client proteins Akt, BRAF, RAF-1, cyclin B and cdc25 proteins. Additionally, it reduced Hsp70, Hsp90 paralog, GRP94 and HSF1 levels. KU135 induced strong G2/M cell cycle arrest, associated with decreased expression of cdc25c, cyclin B and increased phosphorylation of cdc25c. These finding show that KU135 reduced cell survival, proliferation, and induces apoptosis in melanoma cells. We suggest that KU135 may be a potential candidate for cancer therapy against melanoma

Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vector Culex quinquefasciatus

Abstract: Culex quinquefasciatus plays an important role in transmission of vector-borne diseases of public health importance, including lymphatic filariasis (LF), as well as many arboviral diseases. Currently, efforts to tackle C. quinquefasciatus vectored diseases are based on either mass drug administration (MDA) for LF, or insecticide-based interventions. Widespread and intensive insecticide usage has resulted in increased resistance in mosquito vectors, including C. quinquefasciatus. Herein, the transcriptome profile of Ugandan bendiocarb-resistant C. quinquefasciatus was explored to identify candidate genes associated with insecticide resistance. High levels of insecticide resistance were observed for five out of six insecticides tested, with the lowest mortality (0.97%) reported to permethrin, while for DDT, lambdacyhalothrin, bendiocarb and deltamethrin the mortality rate ranged from 1.63–3.29%. Resistance to bendiocarb in exposed mosquitoes was marked, with 2.04% mortality following 1 h exposure and 58.02% after 4 h. Genotyping of the G119S Ace-1 target site mutation detected a highly significant association (p 8-fold increase vs unexposed controls). These results provide evidence that bendiocarb resistance in Ugandan C. quinquefasciatus is mediated by both target-site mechanisms and over-expression of detoxification enzymes

Climate Change – Refining the Impacts for Ireland: STRIVE Report (2001-CD-C3-M1) ISBN: 978-1-84095-297-1

International Context: As a mid-latitude country Ireland can expect its future temperature changes to mirror quite closely those of the globe as a whole. Best estimates of global temperature change by the end of the present century are currently in the region 1.8–4.0°C1. Regional Context: Weighted Ensemble Downscaling from Global Climate Models Global climate models (GCMs) have greatly improved in reliability and resolution as computing power has increased and better inputs from earth observation have become available. Despite this, they remain too coarse in terms of their grid size to enable climate scenarios at the scale necessary for impact analysis to be achieved. This study employs a statistical downscaling approach to overcome these difficulties and also to provide new information on model uncertainty with a view to reducing uncertainty in key sectors such as water resource management, agriculture and biodiversity

Reverse-engineering history : re-presenting the Chichester tablet using laser scanning and 3D printing

3D digitization methods have become essential tools in cultural heritage practice. Methods like laser scanning and photogrammetry are being widely applied for the conservation of priceless objects and for enabling audience engagement with history. Such data have value as a new wave of multisensory museum practice ripples through the sector and could provide a perfect use for the enormous corpus of 3D data in cultural heritage. This paper documents such an application, where laser scanning has been used in conjunction with 3D printing to re-present the Chichester Roman tablet, an object of key importance in early Romano-British history, to new audiences. It details the process used to digitize the tablet and recreate different versions of its missing text and its state of preservation. It describes how such data can play a role beyond just documentation. Discussed is how such approaches enrich families’ engagement in cultural heritage and how such material can used as didactic material in higher education

Stage-specific miRNAs regulate gene expression associated with growth, development and parasite-host interaction during the intra-mammalian migration of the zoonotic helminth parasite Fasciola hepatica

Abstract Background MiRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression in organisms ranging from viruses to mammals. There is great relevance in understanding how miRNAs regulate genes involved in the growth, development, and maturation of the many parasitic worms (helminths) that together afflict more than 2 billion people. Results Here, we describe the miRNAs expressed by each of the predominant intra-mammalian development stages of Fasciola hepatica, a foodborne flatworm that infects a wide range of mammals worldwide, most importantly humans and their livestock. A total of 124 miRNAs were profiled, 72 of which had been previously reported and three of which were conserved miRNA sequences described here for the first time. The remaining 49 miRNAs were novel sequences of which, 31 were conserved with F. gigantica and the remaining 18 were specific to F. hepatica. The newly excysted juveniles express 22 unique miRNAs while the immature liver and mature bile duct stages each express 16 unique miRNAs. We discovered several sequence variant miRNAs (IsomiRs) as well as miRNA clusters that exhibit strict temporal expression paralleling parasite development. Target analysis revealed the close association between miRNA expression and stage-specific changes in the transcriptome; for example, we identified specific miRNAs that target parasite proteases known to be essential for intestinal wall penetration (cathepsin L3). Moreover, we demonstrate that miRNAs fine-tune the expression of genes involved in the metabolic pathways that allow the parasites to move from an aerobic external environment to the anerobic environment of the host. Conclusions These results provide novel insight into the regulation of helminth parasite development and identifies new genes and miRNAs for therapeutic development to limit the virulence and pathogenesis caused by F. hepatica. </jats:sec

Context-Dependent Medicinal Effects of Anabasine and Infection-Dependent Toxicity in Bumble Bees

Background Floral phytochemicals are ubiquitous in nature, and can function both as antimicrobials and as insecticides. Although many phytochemicals act as toxins and deterrents to consumers, the same chemicals may counteract disease and be preferred by infected individuals. The roles of nectar and pollen phytochemicals in pollinator ecology and conservation are complex, with evidence for both toxicity and medicinal effects against parasites. However, it remains unclear how consistent the effects of phytochemicals are across different parasite lineages and environmental conditions, and whether pollinators actively self-medicate with these compounds when infected. Approach Here, we test effects of the nectar alkaloid anabasine, found in Nicotiana, on infection intensity, dietary preference, and survival and performance of bumble bees (Bombus impatiens). We examined variation in the effects of anabasine on infection with different lineages of the intestinal parasite Crithidia under pollen-fed and pollen-starved conditions. Results We found that anabasine did not reduce infection intensity in individual bees infected with any of four Crithidia lineages that were tested in parallel, nor did anabasine reduce infection intensity in microcolonies of queenless workers. In addition, neither anabasine nor its isomer, nicotine, was preferred by infected bees in choice experiments, and infected bees consumed less anabasine than did uninfected bees under no-choice conditions. Furthermore, anabasine exacerbated the negative effects of infection on bee survival and microcolony performance. Anabasine reduced infection in only one experiment, in which bees were deprived of pollen and post-pupal contact with nestmates. In this experiment, anabasine had antiparasitic effects in bees from only two of four colonies, and infected bees exhibited reduced—rather than increased—phytochemical consumption relative to uninfected bees. Conclusions Variation in the effect of anabasine on infection suggests potential modulation of tritrophic interactions by both host genotype and environmental variables. Overall, our results demonstrate that Bombus impatiens prefer diets without nicotine and anabasine, and suggest that the medicinal effects and toxicity of anabasine may be context dependent. Future research should identify the specific environmental and genotypic factors that determine whether nectar phytochemicals have medicinal or deleterious effects on pollinators

A Systematic Protocol for the Characterization of Hsp90 Modulators

This is the author's accepted manuscript. Made available by the permission of the publisher.Several Hsp90 modulators have been identified including the N-terminal ligand geldanamycin (GDA), the C-terminal ligand novobiocin (NB), and the co-chaperone disruptor celastrol. Other Hsp90 modulators elicit a mechanism of action that remains unknown. For example, the natural product gedunin and the synthetic anti-spermatogenic agent H2-gamendazole, recently identified Hsp90 modulators, manifest biological activity through undefined mechanisms. Herein, we report a series of biochemical techniques used to classify such modulators into identifiable categories. Such studies provided evidence that gedunin and H2-gamendazole both modulate Hsp90 via a mechanism similar to celastrol, and unlike NB or GDA