26 research outputs found

    A potent antimalarial benzoxaborole targets a Plasmodium falciparum cleavage and polyadenylation specificity factor homologue.

    Get PDF
    Benzoxaboroles are effective against bacterial, fungal and protozoan pathogens. We report potent activity of the benzoxaborole AN3661 against Plasmodium falciparum laboratory-adapted strains (mean IC50 32 nM), Ugandan field isolates (mean ex vivo IC50 64 nM), and murine P. berghei and P. falciparum infections (day 4 ED90 0.34 and 0.57 mg kg-1, respectively). Multiple P. falciparum lines selected in vitro for resistance to AN3661 harboured point mutations in pfcpsf3, which encodes a homologue of mammalian cleavage and polyadenylation specificity factor subunit 3 (CPSF-73 or CPSF3). CRISPR-Cas9-mediated introduction of pfcpsf3 mutations into parental lines recapitulated AN3661 resistance. PfCPSF3 homology models placed these mutations in the active site, where AN3661 is predicted to bind. Transcripts for three trophozoite-expressed genes were lost in AN3661-treated trophozoites, which was not observed in parasites selected or engineered for AN3661 resistance. Our results identify the pre-mRNA processing factor PfCPSF3 as a promising antimalarial drug target

    Development of a Highly Selective Plasmodium falciparum Proteasome Inhibitor with Anti-malaria Activity in Humanized Mice.

    Get PDF
    Plasmodium falciparum proteasome (Pf20S) inhibitors are active against Plasmodium at multiple stages-erythrocytic, gametocyte, liver, and gamete activation stages-indicating that selective Pf20S inhibitors possess the potential to be therapeutic, prophylactic, and transmission-blocking antimalarials. Starting from a reported compound, we developed a noncovalent, macrocyclic peptide inhibitor of the malarial proteasome with high species selectivity and improved pharmacokinetic properties. The compound demonstrates specific, time-dependent inhibition of the β5 subunit of the Pf20S, kills artemisinin-sensitive and artemisinin-resistant P. falciparum isolates in vitro and reduces parasitemia in humanized, P. falciparum-infected mice

    Setting our sights on infectious diseases

    Get PDF
    In May 2019, the Wellcome Centre for Anti-Infectives Research (WCAIR) at the University of Dundee, UK, held an international conference with the aim of discussing some key questions around discovering new medicines for infectious diseases and a particular focus on diseases affecting Low and Middle Income Countries. There is an urgent need for new drugs to treat most infectious diseases. We were keen to see if there were lessons that we could learn across different disease areas and between the preclinical and clinical phases with the aim of exploring how we can improve and speed up the drug discovery, translational, and clinical development processes. We started with an introductory session on the current situation and then worked backward from clinical development to combination therapy, pharmacokinetic/pharmacodynamic (PK/PD) studies, drug discovery pathways, and new starting points and targets. This Viewpoint aims to capture some of the learnings

    Secuenciacion y analisis funcional de 26 kb del DNA de Saccharomyces cerevisiae y caracterizacion del gen responsable del fenotipo del mutante DGT1-1

    No full text
    Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

    Diverse evolutionary pathways challenge the use of collateral sensitivity as a strategy to suppress resistance

    No full text
    Drug resistance remains a major obstacle to malaria control and eradication efforts, necessitating the development of novel therapeutic strategies to treat this disease. Drug combinations based on collateral sensitivity, wherein resistance to one drug causes increased sensitivity to the partner drug, have been proposed as an evolutionary strategy to suppress the emergence of resistance in pathogen populations. In this study, we explore collateral sensitivity between compounds targeting the Plasmodium dihydroorotate dehydrogenase (DHODH). We profiled the cross-resistance and collateral sensitivity phenotypes of several DHODH mutant lines to a diverse panel of DHODH inhibitors. We focus on one compound, TCMDC-125334, which was active against all mutant lines tested, including the DHODH C276Y line, which arose in selections with the clinical candidate DSM265. In six selections with TCMDC-125334, the most common mechanism of resistance to this compound was copy number variation of the dhodh locus, although we did identify one mutation, DHODH I263S, which conferred resistance to TCMDC-125334 but not DSM265. We found that selection of the DHODH C276Y mutant with TCMDC-125334 yielded additional genetic changes in the dhodh locus. These double mutant parasites exhibited decreased sensitivity to TCMDC-125334 and were highly resistant to DSM265. Finally, we tested whether collateral sensitivity could be exploited to suppress the emergence of resistance in the context of combination treatment by exposing wildtype parasites to both DSM265 and TCMDC-125334 simultaneously. This selected for parasites with a DHODH V532A mutation which were cross-resistant to both compounds and were as fit as the wildtype parent in vitro. The emergence of these cross-resistant, evolutionarily fit parasites highlights the mutational flexibility of the DHODH enzyme

    Identification of fast-acting 2,6-disubstituted imidazopyridines that are efficacious in the In Vivo humanized Plasmodium falciparum nodscidil2rgamma (null) mouse model of malaria

    No full text
    Optimization of a chemical series originating from whole-cell phenotypic screening against the human malaria parasite, Plasmodium falciparum, led to the identification of two promising 2,6-disubstituted imidazopyridine compounds, 43 and 74. These compounds exhibited potent activity against asexual blood stage parasites that, together with their in vitro absorption, distribution, metabolism, and excretion (ADME) properties, translated to in vivo efficacy with clearance of parasites in the PfSCID mouse model for malaria within 48 h of treatment

    Prev Chronic Dis

    Get PDF
    IntroductionHealth-risk behaviors such as eating poorly, being physically inactive, and smoking contribute to the leading causes of morbidity and mortality in the United States and are often established during adolescence and young adulthood. The objectives of this study were to characterize the health-risk behaviors of young adults (aged 18\u201324 years) using a large population-based survey of Americans and to determine if behaviors of this group differ by weight category, as assessed by body mass index (BMI).MethodsPrevalence estimates for selected health-risk behaviors were calculated for respondents aged 18 to 24 years to the 2003 Behavioral Risk Factor Surveillance System (BRFSS). Respondents were categorized by BMI, and comparisons between sex and race and ethnicity were made within the overweight and obese categories.ResultsMore than three quarters (78.4%) of respondents consumed fewer than five fruits and vegetables per day, 43.2% reported insufficient or no physical activity, 28.9% were current smokers, 30.1% reported binge drinking, and 11.9% reported frequent mental distress. One quarter (26.1%) of respondents were overweight, and 13.6% were obese. Of obese young adults, 67.2% reported that they currently were trying to lose weight; however, only 24.3% reported having received professional advice to lose weight. More obese women (34.2%) than obese men (16.7%) reported having received professional advice to lose weight. Only 19.1% of obese non-Hispanic white respondents had received professional advice to lose weight compared with 28.0% of obese Hispanic respondents and 30.6% of obese non-Hispanic black respondents.ConclusionMany young adults engage in unhealthy behaviors, and differences exist in health-risk behaviors by BMI category and specifically by sex and race and ethnicity within BMI categories. The transition from adolescence to adulthood may be an opportune time for intervening to prevent future chronic disease.2007720
    corecore