Abstract
The identification of G-quadruplex (G4) binding proteins and insights into their mechanism of action are important for understanding the regulatory functions of G4 structures. Here, we ...performed an unbiased affinity-purification assay coupled with mass spectrometry and identified 30 putative G4 binding proteins from the fission yeast Schizosaccharomyces pombe. Gene ontology analysis of the molecular functions enriched in this pull-down assay included mRNA binding, RNA helicase activity, and translation regulator activity. We focused this study on three of the identified proteins that possessed putative arginine-glycine-glycine (RGG) domains, namely the Stm1 homolog Oga1 and the DEAD box RNA helicases Dbp2 and Ded1. We found that Oga1, Dbp2, and Ded1 bound to both DNA and RNA G4s in vitro. Both Dbp2 and Ded1 bound to G4 structures through the RGG domain located in the C-terminal region of the helicases, and point mutations in this domain weakened the G4 binding properties of the helicases. Dbp2 and Ded1 destabilized less thermostable G4 RNA and DNA structures, and this ability was independent of ATP but dependent on the RGG domain. Our study provides the first evidence that the RGG motifs in DEAD box helicases are necessary for both G4 binding and G4 destabilization.
Multiple factors influence translation termination efficiency, including nonsense codon identity and immediate context. To determine whether the relative position of a nonsense codon within an open ...reading frame (ORF) influences termination efficiency, we quantitate the production of prematurely terminated and/or readthrough polypeptides from 26 nonsense alleles of 3 genes expressed in yeast. The accumulation of premature termination products and the extent of readthrough for the respective premature termination codons (PTCs) manifest a marked dependence on PTC proximity to the mRNA 3′ end. Premature termination products increase in relative abundance, whereas readthrough efficiencies decrease progressively across different ORFs, and readthrough efficiencies for a PTC increase in response to 3′ UTR lengthening. These effects are eliminated and overall translation termination efficiency decreases considerably in cells harboring pab1 mutations. Our results support a critical role for poly(A)-binding protein in the regulation of translation termination and also suggest that inefficient termination is a trigger for nonsense-mediated mRNA decay (NMD).
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•Premature translational termination manifests position effects in yeast mRNAs•Termination increases and readthrough decreases as stop codons approach the ORF 3′ end•Stop codon proximity to 3′ poly(A)-binding protein regulates termination efficiency•Positional variation and termination dependence on Pab1 support an NMD faux-UTR model
Premature termination codons (PTCs) trigger translational termination and can promote mRNA decay. Wu et al. insert PTCs at multiple locations in yeast genes and find that their termination efficiencies increase with proximity to ORF 3′ ends and that this positional effect on termination is modulated through mRNA-associated poly(A)-binding protein.
•Fish oil products from a large database largely meet regulatory oxidation limits.•Fish oil products have oxidation results comparable to other dietary oils.•Some flavourings can interfere with the ...p-anisidine value method in oils.
Fish oil (FO) products constitute good sources of omega-3 fats. Oxidation data from a large third-party database of 1900 + globally-sourced FO samples were assessed. In FO products, for peroxide value (PV), 13.9% exceeded 5 mEq O2/kg (2.2% >10); for acid value (AcV) 2.1% exceeded 3 mg KOH/g, while for p-anisidine value (pAV) in unflavoured oils, 6.1% exceeded 20, (3.8% >30), and 8.8% exceeded TOTOX limits (26). Additionally, we compared FO with other dietary oils. The FO median PV was similar to those of algal and sunflower oils, 4.8-fold greater than krill oil, and 5.2-fold less than extra-virgin olive oil. The median pAV differed non-significantly among oils. The FO median AcV was similar to those of algal and extra-virgin olive oils, 3.4-fold greater than sunflower oil, and 11.9-fold less than krill oil. This study has provided new insight that retail FO products predominantly meet regulatory guidelines and are comparable in oxidative status to other dietary oils.
The response of titin to mechanical forces is a major determinant of the function of the heart. When placed under a pulling force, the unstructured regions of titin uncoil while its immunoglobulin ...(Ig) domains unfold and extend. Using single-molecule atomic force microscopy, we show that disulfide isomerization reactions within Ig domains enable a third mechanism of titin elasticity. Oxidation of Ig domains leads to non-canonical disulfide bonds that stiffen titin while enabling force-triggered isomerization reactions to more extended states of the domains. Using sequence and structural analyses, we show that 21% of titin's I-band Ig domains contain a conserved cysteine triad that can engage in disulfide isomerization reactions. We propose that imbalance of the redox status of myocytes can have immediate consequences for the mechanical properties of the sarcomere via alterations of the oxidation state of titin domains.
Forty-seven fish oil products available on the New Zealand market were analyzed for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, as well as for oxidative status in a ...collaborative effort by several analytical laboratories. Of the tested products, 72%, 86% and 77% complied with voluntary industry-set maximum limits on Peroxide Value (PV), para-Anisidine Value (p-AV), and TOTOX, respectively. 91% of the products complied with EPA/DHA content claims. All fish oils complied with a p-AV limit of 30, 98% with a PV limit of 10 meq O
/kg, and 96% with a calculated TOTOX value of 50, which are less stringent limits used by the European and British Pharmacopeia and the Australian authorities. The results are in stark contrast to the very low percentage of fish oil products reported to be in compliance with primary oxidation limits and EPA/DHA content by a recently published assessment of fish oil supplements in New Zealand. Possible reasons for this discrepancy are evaluated and discussed.
Atypical hemolytic uremic syndrome (aHUS) is a rare but severe disorder that frequently has a genetic component and results from the overactivation of the alternative complement pathway. As research ...moves toward improved diagnosis and therapy of aHUS, it will be important to better understand its epidemiology. Our objective was to conduct a systematic literature review to assess the incidence and prevalence estimates of aHUS globally. A comprehensive literature search was conducted in Embase and MEDLINE. Additionally, practice guidelines, databases of national/international organizations, and regulatory agencies were searched. From 2960 publications identified via MEDLINE and Embase, 105 publications were eligible for full-text screening, and a total of eight full-text articles met eligibility criteria for inclusion. Regional epidemiologic estimates were obtained for Europe and Oceania. Country-specific data were available for France, Norway, Australia, and Italy. Four of the identified studies reported on the prevalence of aHUS, prevalence in the age group of 20 years or younger was ranging from 2.2 to 9.4 per million population, while the only study that reported prevalence in all ages showed a prevalence of 4.9 per million population. Six studies reported on the incidence of aHUS, annual incidence in the age group of 20 years or younger was ranging from 0.26 to 0.75 per million population, and for all ages, annual incidence was ranging from 0.23 to 1.9 per million population. To our knowledge, this is the first systematic review conducted to provide a comprehensive overview of global incidence and prevalence estimates of aHUS. In general, incidence estimates were similar across all the studies; however, prevalence data were found to be more variable. Study limitations were related to inconsistencies in the definitions of aHUS between studies and also a dearth of epidemiological studies assessing incidence and prevalence of aHUS outside of Europe.
•Incidence and prevalence were combined across 4 continents and 15 countries.•Incidence estimates were similar across regions; prevalence was more variable.•Prevalence of pediatric MS was found to be ...lowest in the Asia region.•Lack of estimates from other large regions (e.g. Africa, Russia, and Australia).
Multiple sclerosis (MS) is a debilitating immune disease leading to demyelination, neurodegeneration, and chronic inflammation of the central nervous system. Pediatric MS is a rare form of the disease and effects approximately 2–10% of individuals with MS. Diagnostic criteria and therapies are continuously evolving, thus it is imperative to further understand the epidemiology and subsequently global and regional disease burden of pediatric MS. Our objective was to conduct a systematic literature review and meta-analysis to assess the incidence and prevalence of pediatric MS globally. Subgroup analyses were also conducted by region and diagnostic criteria used to ascertain cases.
A systematic literature review was conducted using searches run in EMBASE and MEDLINE. A hand search was also conducted, and the bibliographies of any relevant articles were reviewed for any studies potentially not captured by the databases. A random effects model was used to combine epidemiological estimates across studies. Subgroup analyses by region and diagnostic criteria were performed in instances when three or more studies were available for analyses.
A total of 2,965 publications were identified, of which 187 were eligible for full-text screening. A total of 21 full-text articles met the eligibility criteria and were included for data extraction, with 18 studies included for meta-analysis. Regional epidemiologic estimates were obtained for North America, Europe, Middle East, and Asia. Country specific data was available for Canada, United States, Germany, Iceland, Netherlands, Sardinia, Slovenia, UAE/Abu Dhabi, Iran, Israel, Jordan, Kuwait, Tunisia, Taiwan, and Japan. Thirteen studies representing 12 countries reported incidence of pediatric MS. Overall incidence ranged from 0.05 to 2.85 and pooled global incidence was calculated to be 0.87 (95% CI: 0.35–1.40) per 100,000 individuals annually. Ten studies representing 10 countries reported on the prevalence of pediatric MS. Overall prevalence ranged from 0.69 to 26.92 per 100,000 individuals and pooled global prevalence was calculated to be 8.11 (95% CI: 2.28–13.93) per 100,000 people.
To our knowledge, this is the first meta-analysis conducted to provide pooled estimates of incidence and prevalence estimates of pediatric MS globally. In general, incidence estimates were similar across regions; however, prevalence was found to be more variable. Noticeable gaps in evidence include a lack of pediatric MS estimates from other large regions of the world such as Africa, South America, Russia, and Australia. Moreover, there is a need for more population-based studies using the most up to date diagnostic criteria.
There is vigorous debate as to whether influential social media platforms like Twitter and Facebook should censor objectionable posts by prominent individuals in the United States and elsewhere. A ...tentative middle ground is employing content moderation to signal to social media audiences that certain posts may contain objectionable information through the mechanism of flagging. Existing studies have mainly examined the effect of flagging regular users' content. To add to this emerging literature stream, we examine the effect of flagging when the underlying content is produced by a prominent individual. Leveraging Twitter's moderation activities on former U.S. President Donald Trump's tweets as our empirical setting, we employ three machine learning algorithms to estimate the effect of flagging Trump's tweets. We explore preliminary evidence as to whether these posts were retweeted less or more than expected. Our results indicate that the flagged tweets were retweeted at higher rates than expected. Our findings suggest that flagging content of prominent individuals on social media might be ineffective or even counterproductive in curbing the spread of content deemed objectionable by social media companies.
Historically healthcare has been delivered offline (e.g., physician consultations, mental health counseling services). It is widely understood that healthcare lags behind other industries (e.g., ...financial, transportation) whom have already incorporated digital technologies in their workflow. However, this is changing with the recent emergence of digital therapeutics (DTx) helping to bring healthcare services online. To promote adoption, healthcare providers need to be educated regarding the digital therapy to allow for proper prescribing. But of equal importance is affordability and many countries rely on reimbursement support from the government and insurance agencies. Here we briefly explore how national reimbursement agencies or non-profits across six countries (Canada, United States of America, United Kingdom, Germany, France, Australia) handle DTx submissions and describe the potential impact of digital therapeutics on current health technology assessment (HTA) frameworks. A targeted review to identify HTA submissions and guidelines from national reimbursement agencies or non-profits was conducted. We reviewed guidelines from the Institute for Clinical and Economic Review (ICER) in the USA, the Canadian Agency for Drugs and Technologies in Health (CADTH) in Canada, the National Institute for Health and Care Excellence (NICE) in the United Kingdom (UK), the Institute for Quality and Efficiency in Health Care (IQWIG) in Germany, Haute Autorité de Santé (HAS) in France, and the Pharmaceutical Benefits Advisory Committee (PBAC) in Australia. Our review identified one set of guidelines developed by NICE in the UK. The guidelines by NICE outlined an evidence standards framework for digital health technologies (DHT). Depending on the organizational impact, financial commitment, and economic risk for the payer, different economic analyses are required. Economic analyses levels are separated into 3 categories, basic, low financial commitment, and high financial commitment. All economic analyses levels require a budget impact analysis. A cost-utility analysis is recommended for DHTs categorized in the high financial commitment category. Whereas, for DHTs that are in the low financial commitment category, a cost-consequence analysis is typically recommended. No HTA guidelines for DTx submissions were identified for the remaining countries (Canada, USA, Germany, France, and Australia)
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