43 research outputs found
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Off‐target inhibition of NGLY1 by the poly‐caspase inhibitor Z‐VAD‐fmk induces cellular autophagy
The pan-caspase inhibitor Z-VAD-fmk acts as an inhibitor of peptide:N-glycanase (NGLY1); an endoglycosidase which cleaves N-inked glycans from glycoproteins exported from the endoplasmic reticulum (ER) during ER-associated degradation (ERAD). Both pharmacological N-glycanase inhibition by Z-VAD-fmk and siRNA-mediated knockdown (KD) of NGLY1 induce GFP-LC3 positive puncta in HEK 293 cells. Activation of ER stress markers or induction of reactive oxygen species (ROS) are not observed under either condition. Moreover, Ca2+ handling is unaffected when observing release from intracellular stores. Under conditions of pharmacological NGLY1 inhibition or NGLY1 KD, upregulation of autophagosome formation without impairment of autophagic flux is observed. Enrichment of autophagosomes by immunoprecipitation (IP) and mass spectrometry-based proteomics analysis reveal comparable autophagosomal protein content. Gene ontology analysis of proteins enriched in autophagosome IPs shows overrepresentation of factors involved in protein translation, localization and targeting, RNA degradation and protein complex disassembly. Upregulation of autophagy represents a cellular adaptation to NGLY1 inhibition or KD, and ATG13-deficient mouse embryonic fibroblasts (MEFs) show reduced viability under these conditions. In contrast, treatment with pan-caspase inhibitor, Q-VD-OPh does not induce cellular autophagy. Therefore, experiments with Z-VAD-fmk are complicated by the effects of NGLY1 inhibition, including induction of autophagy, and Q-VD-OPh represents an alternative caspase inhibitor free from this limitation
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NGLY1 knockdown or pharmacological inhibition induces cellular autophagy
Pan-caspase inhibitor Z-VAD-fmk acts as an inhibitor of peptide:N-glycanase (NGLY1); an endoglycosidase which cleaves N-linked glycans from glycoproteins exported from the endoplasmic reticulum during ER-associated degradation (ERAD). Pharmacological N-glycanase inhibition by Z-VAD-fmk or siRNA knockdown (KD) induces GFP-LC3 positive puncta in HEK 293 cells. Activation of ER stress markers or reactive oxygen species (ROS) induction are not observed. In NGLY1 inhibition or KD, upregulation of autophagosome formation without impairment of autophagic flux are observed. Enrichment and proteomics analysis of autophagosomes after Z-VAD-fmk treatment or NGLY1 KD reveals comparable autophagosomal protein content. Upregulation of autophagy represents a cellular adaptation to NGLY1 inhibition or KD, and ATG13-deficient mouse embryonic fibroblasts (MEFs) show reduced viability under these conditions. In contrast, treatment with pan-caspase inhibitor, Q-VD-OPh does not induce cellular autophagy. Therefore, experiments with Z-VAD-fmk are complicated by the effects of NGLY1 inhibition and Q-VD-OPh represents an alternative caspase inhibitor free from this limitation
Second-generation nitazoxanide derivatives: thiazolides are effective inhibitors of the influenza A virus
Aim: The only small molecule drugs currently available for treatment of influenza A virus (IAV) are M2 ion channel blockers and sialidase inhibitors. The prototype thiazolide, nitazoxanide, has successfully completed Phase III clinical trials against acute uncomplicated influenza. Results: We report the activity of seventeen thiazolide analogs against A/PuertoRico/8/1934(H1N1), a laboratory-adapted strain of the H1N1 subtype of IAV, in a cell culture-based assay. A total of eight analogs showed IC50s in the range of 0.14–5.0 μM. Additionally a quantitative structure–property relationship study showed high correlation between experimental and predicted activity based on a molecular descriptor set. Conclusion: A range of thiazolides show useful activity against an H1N1 strain of IAV. Further evaluation of these molecules as potential new small molecule therapies is justified
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Enzymatic glycosylation involving fluorinated carbohydrates
Fluorinated carbohydrates, where one (or more) fluorine atom(s) have been introduced into a carbohydrate structure, typically through deoxyfluorination chemistry, have a wide range of applications in the glycosciences. Fluorinated derivatives of galactose, glucose, N-acetylgalactosamine, N-acetylglucosamine, talose, fucose and sialic acid have been employed as either donor or acceptor substrates in glycosylation reactions. Fluorinated donors can be synthesised by synthetic methods or produced enzymatically from chemically fluorinated sugars. The latter process is mediated by enzymes such as kinases, phosphorylases and nucleotidyltransferases. Fluorinated donors produced by either method can subsequently be used in glycosylation reactions mediated by glycosyltransferases, or phosphorylases yielding fluorinated oligosaccharide or glycoconjugate products. Fluorinated acceptor substrates are typically synthesised chemically. Glycosyltransferases are most commonly used in conjunction with natural donors to further elaborate fluorinated acceptor substrates. Glycoside hydrolases are used with either fluorinated donors or acceptors. The activity of enzymes towards fluorinated sugars is often lower than towards the natural sugar substrates irrespective of donor or acceptor. This may be in part attributed to elimination of the contribution of the hydroxyl group to the binding of the substrate to enzymes. However, in many cases, enzymes still maintain a significant activity, and reactions may be optimised where necessary, enabling enzymes to be used more successfully in the production of fluorinated carbohydrates. This review describes the current state of the art regarding chemoenzymatic production of fluorinated carbohydrates, focusing specifically on examples of the enzymatic production of activated fluorinated donors and enzymatic glycosylation involving fluorinated sugars as either glycosyl donors or acceptors
Development of an amplicon-based sequencing approach in response to the global emergence of mpox
The 2022 multicountry mpox outbreak concurrent with the ongoing Coronavirus Disease 2019 (COVID-19) pandemic further highlighted the need for genomic surveillance and rapid pathogen whole-genome sequencing. While metagenomic sequencing approaches have been used to sequence many of the early mpox infections, these methods are resource intensive and require samples with high viral DNA concentrations. Given the atypical clinical presentation of cases associated with the outbreak and uncertainty regarding viral load across both the course of infection and anatomical body sites, there was an urgent need for a more sensitive and broadly applicable sequencing approach. Highly multiplexed amplicon-based sequencing (PrimalSeq) was initially developed for sequencing of Zika virus, and later adapted as the main sequencing approach for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we used PrimalScheme to develop a primer scheme for human monkeypox virus that can be used with many sequencing and bioinformatics pipelines implemented in public health laboratories during the COVID-19 pandemic. We sequenced clinical specimens that tested presumptively positive for human monkeypox virus with amplicon-based and metagenomic sequencing approaches. We found notably higher genome coverage across the virus genome, with minimal amplicon drop-outs, in using the amplicon-based sequencing approach, particularly in higher PCR cycle threshold (Ct) (lower DNA titer) samples. Further testing demonstrated that Ct value correlated with the number of sequencing reads and influenced the percent genome coverage. To maximize genome coverage when resources are limited, we recommend selecting samples with a PCR Ct below 31 Ct and generating 1 million sequencing reads per sample. To support national and international public health genomic surveillance efforts, we sent out primer pool aliquots to 10 laboratories across the United States, United Kingdom, Brazil, and Portugal. These public health laboratories successfully implemented the human monkeypox virus primer scheme in various amplicon sequencing workflows and with different sample types across a range of Ct values. Thus, we show that amplicon-based sequencing can provide a rapidly deployable, cost-effective, and flexible approach to pathogen whole-genome sequencing in response to newly emerging pathogens. Importantly, through the implementation of our primer scheme into existing SARS-CoV-2 workflows and across a range of sample types and sequencing platforms, we further demonstrate the potential of this approach for rapid outbreak response.This publication was made possible by
CTSA Grant Number UL1 TR001863 from the
National Center for Advancing Translational
Science (NCATS), a component of the National
Institutes of Health (NIH) awarded to CBFV. INSA
was partially funded by the HERA project (Grant/
2021/PHF/23776) supported by the European
Commission through the European Centre for
Disease Control (to VB).info:eu-repo/semantics/publishedVersio
Effectiveness of a behavioral incentive scheme linked to goal achievement: study protocol for a randomized controlled trial
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication
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Blending virtual reality with traditional approaches to encourage engagement with core chemistry concepts relevant to an undergraduate pharmacy curriculum
Students studying Pharmacy often lack motivation to engage with chemical principles. In particular, they often find fundamental chemical concepts such as the visualization of three-dimensional structures challenging. This programme description reports the design and implementation of a teaching session where stand-alone virtual reality (VR) technology was offered alongside traditional methods of instruction in an attempt to encourage students to engage with fundamental chemistry concepts relating to the three-dimensional structures of drug molecules. By using VR technology in combination with paper-based in-class exercises and supporting material delivered via a virtual learning environment, we demonstrate that virtual reality could be used to both reinforce learning and enhance engagement with a topic which students often find challenging. A blended approach employing different methods of delivery presents the advantage that it allows the user control over the level of interaction with each individual element. As such, virtual reality becomes a valuable instructional tool rather the focus of the session or a distraction.
To evaluate the sessions, we collected student feedback using a “ballot-box” system where students could provide anonymous free response comments. Feedback from the session was overwhelmingly positive and it was noted that the optional use of VR technology kept students engaged in tackling paper-based exercises in an area of curriculum which learners often find difficult.
It is noted that a blended approach can help to overcome several of the barriers to the use of virtual reality in a classroom setting. In addition, it highlights that effective deployment of such technology is both viable and beneficial on a classroom scale. In the future, we hope to apply these methods to other parts of the curriculum where students would benefit from being able to visualize three-dimensional structures
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Glycoprotein misfolding in the endoplasmic reticulum: identification of released oligosaccharides reveals a second ER-associated degradation pathway for Golgi-retrieved proteins
Endoplasmic reticulum-associated degradation (ERAD) is a key cellular process whereby misfolded proteins are removed from the endoplasmic reticulum (ER) for subsequent degradation by the ubiquitin/proteasome system. In the present work, analysis of the released, free oligosaccharides (FOS) derived from all glycoproteins undergoing ERAD, has allowed a global estimation of the mechanisms of this pathway rather than following model proteins through degradative routes. Examining the FOS produced in endomannosidase-compromised cells following α-glucosidase inhibition has revealed a mechanism for clearing Golgi-retrieved glycoproteins that have failed to enter the ER quality control cycle. The Glc3Man7GlcNAc2 FOS species has been shown to be produced in the ER lumen by a mechanism involving a peptide: N-glycanase-like activity, and its production was sensitive to disruption of Golgi-ER trafficking. The detection of this oligosaccharide was unaffected by the overexpression of EDEM1 or cytosolic mannosidase, both of which increased the production of previously characterised cytosolically localised FOS. The lumenal FOS identified are therefore distinct in their production and regulation compared to FOS produced by the conventional route of misfolded glycoproteins directly removed from the ER. The production of such lumenal FOS is indicative of a novel degradative route for cellular glycoproteins that may exist under certain conditions
Great \u27app-eal\u27 but not there yet: a review of iPhone nutrition applications relevant to child weight management
Aims: There is increasing interest in the use of smartphone applications (apps) for delivering child obesity management interventions and supporting lifestyle behaviour change; however, there has been very little academic research on their development. Our aim is to review nutrition-related apps designed for children currently available in Australia for their usefulness in education or support behavioural interventions for child obesity. Methods: Apps available for download in iTunes Australia between 2 April and 3 June 2013 which were suitable for children >12 years were identified. Key words were chosen to identify apps applicable to children, focusing on nutrition. Results: A total of 27 apps were included. Most apps (24/27) were not based on evidence-informed recommendations. A third of apps were developed in the USA (n = 10; 37%) and were free (67%), nine apps required upfront payment, with a mean cost of A0.99-$A7.49). The most common nutrition features were the promotion of energy balance (n = 12 apps) and guidance on appropriate portion size (n = 15). The most common behaviour change feature was goal setting (n = 15). The five apps that scored most highly against the characteristics reviewed were: Calorie Counter Pro by My Net Diary, Weight Watchers, Swap It Don\u27t Stop It, Control My Weight by CalorieKing and Rate What I Ate-Photo Diet Tracker. Conclusions: Very few apps were identified that could be used in education or support behavioural interventions for child obesity. There is a need to harness this technology and evaluate the applicability and use within childhood obesity research interventions