37 research outputs found
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Pan-active imidazolopiperazine antimalarials target the Plasmodium falciparum intracellular secretory pathway.
A promising new compound class for treating human malaria is the imidazolopiperazines (IZP) class. IZP compounds KAF156 (Ganaplacide) and GNF179 are effective against Plasmodium symptomatic asexual blood-stage infections, and are able to prevent transmission and block infection in animal models. But despite the identification of resistance mechanisms in P. falciparum, the mode of action of IZPs remains unknown. To investigate, we here combine in vitro evolution and genome analysis in Saccharomyces cerevisiae with molecular, metabolomic, and chemogenomic methods in P. falciparum. Our findings reveal that IZP-resistant S. cerevisiae clones carry mutations in genes involved in Endoplasmic Reticulum (ER)-based lipid homeostasis and autophagy. In Plasmodium, IZPs inhibit protein trafficking, block the establishment of new permeation pathways, and cause ER expansion. Our data highlight a mechanism for blocking parasite development that is distinct from those of standard compounds used to treat malaria, and demonstrate the potential of IZPs for studying ER-dependent protein processing
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Recreational physical inactivity and mortality in women with invasive epithelial ovarian cancer: evidence from the Ovarian Cancer Association Consortium
Background: Little is known about modifiable behaviours that may be associated with epithelial ovarian cancer (EOC) survival. We conducted a pooled analysis of 12 studies from the Ovarian Cancer Association Consortium to investigate the association between pre-diagnostic physical inactivity and mortality. Methods: Participants included 6806 women with a primary diagnosis of invasive EOC. In accordance with the Physical Activity Guidelines for Americans, women reporting no regular, weekly recreational physical activity were classified as inactive. We utilised Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) representing the associations of inactivity with mortality censored at 5 years. Results: In multivariate analysis, inactive women had significantly higher mortality risks, with (HR=1.34, 95% CI: 1.18–1.52) and without (HR=1.22, 95% CI: 1.12–1.33) further adjustment for residual disease, respectively. Conclusion: In this large pooled analysis, lack of recreational physical activity was associated with increased mortality among women with invasive EOC
Mutations in the Plasmodium falciparum
Mutations in the Plasmodium falciparum cyclic amine resistance locus (PfCARL) are associated with parasite resistance to the imidazolopiperazines, a potent class of novel antimalarial compounds that display both prophylactic and transmission-blocking activity, in addition to activity against blood-stage parasites. Here, we show that pfcarl encodes a protein, with a predicted molecular weight of 153 kDa, that localizes to the cis-Golgi apparatus of the parasite in both asexual and sexual blood stages. Utilizing clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene introduction of 5 variants (L830V, S1076N/I, V1103L, and I1139K), we demonstrate that mutations in pfcarl are sufficient to generate resistance against the imidazolopiperazines in both asexual and sexual blood-stage parasites. We further determined that the mutant PfCARL protein confers resistance to several structurally unrelated compounds. These data suggest that PfCARL modulates the levels of small-molecule inhibitors that affect Golgi-related processes, such as protein sorting or membrane trafficking, and is therefore an important mechanism of resistance in malaria parasites
Aging Well Among Women Veterans Compared With Non-Veterans in the Women's Health Initiative.
Purpose of the studyTo examine whether Veteran status influences (a) women's survival to age 80 years without disease and disability and (b) indicators of successful, effective, and optimal aging at ages 80 years and older.Design and methodsThe Women's Health Initiative (WHI) enrolled 161,808 postmenopausal women aged 50-79 years from 1993 to 1998. We compared successful aging indicators collected in 2011-2012 via mailed questionnaire among 33,565 women (921 Veterans) who reached the age of 80 years and older, according to Veteran status. A second analysis focused on women with intact mobility at baseline who could have reached age 80 years by December 2013. Multinominal logistic models examined Veteran status in relation to survival to age 80 years without major disease or mobility disability versus having prevalent or incident disease, having mobility disability, or dying prior to age 80 years.ResultsWomen Veterans aged 80 years and older reported significantly lower perceived health, physical function, life satisfaction, social support, quality of life, and purpose in life scale scores compared with non-Veterans. The largest difference was in physical function scores (53.0 for Veterans vs 59.5 for non-Veterans; p < .001). Women Veterans were significantly more likely to die prior to age 80 years than non-Veteran WHI participants (multivariate adjusted odds ratio = 1.20; 95% confidence interval, 1.04-1.38). In both Veteran and non-Veteran women, healthy survival was associated with not smoking, higher physical activity, healthy body weight, and fewer depressive symptoms.ImplicationsIntervening upon smoking, low physical activity, obesity, and depressive symptoms has potential to improve chances for healthy survival in older women including Veterans
Mutations in the Plasmodium falciparum Cyclic Amine Resistance Locus (PfCARL) Confer Multidrug Resistance
Mutations in the Plasmodium falciparum cyclic amine resistance locus (PfCARL) are associated with parasite resistance to the imidazolopiperazines, a potent class of novel antimalarial compounds that display both prophylactic and transmission-blocking activity, in addition to activity against blood-stage parasites. Here, we show that pfcarl encodes a protein, with a predicted molecular weight of 153 kDa, that localizes to the cis-Golgi apparatus of the parasite in both asexual and sexual blood stages. Utilizing clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene introduction of 5 variants (L830V, S1076N/I, V1103L, and I1139K), we demonstrate that mutations in pfcarl are sufficient to generate resistance against the imidazolopiperazines in both asexual and sexual blood-stage parasites. We further determined that the mutant PfCARL protein confers resistance to several structurally unrelated compounds. These data suggest that PfCARL modulates the levels of small-molecule inhibitors that affect Golgi-related processes, such as protein sorting or membrane trafficking, and is therefore an important mechanism of resistance in malaria parasites
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Plasmodium falciparum Cyclic Amine Resistance Locus (PfCARL), a Resistance Mechanism for Two Distinct Compound Classes
MMV007564
is a novel antimalarial benzimidazolyl piperidine chemotype
identified in cellular screens. To identify the genetic determinant
of MMV007564 resistance, parasites were cultured in the presence of
the compound to generate resistant lines. Whole genome sequencing
revealed distinct mutations in the gene named Plasmodium
falciparum cyclic amine resistance locus (<i>pfcarl</i>), encoding a conserved protein of unknown function.
Mutations in <i>pfcarl</i> are strongly associated with
resistance to a structurally unrelated class of compounds, the imidazolopiperazines,
including KAF156, currently in clinical trials. Our data demonstrate
that <i>pfcarl</i> mutations confer resistance to two distinct
compound classes, benzimidazolyl piperidines and imidazolopiperazines.
However, MMV007564 and the imidazolopiperazines, KAF156 and GNF179,
have different timings of action in the asexual blood stage and different
potencies against the liver and sexual blood stages. These data suggest
that <i>pfcarl</i> is a multidrug-resistance gene rather
than a common target for benzimidazolyl piperidines and imidazolopiperazines
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Optimism predicts sustained vigorous physical activity in postmenopausal women☆
Optimism and cynical hostility are associated with health behaviors and health outcomes, including morbidity and mortality. This analysis assesses their association with longitudinal vigorous physical activity (PA) in postmenopausal women of the Women's Health Initiative (WHI). Subjects include 73,485 women nationwide without history of cancer or cardiovascular disease (CVD), and no missing baseline optimism, cynical hostility, or PA data. The Life Orientation Test-Revised Scale measured optimism. A Cook Medley questionnaire subscale measured cynical hostility. Scale scores were divided into quartiles. Vigorous PA three times or more per week was assessed via self-report at study baseline (1994–1998) and through follow-up year 6. Descriptive analysis mapped lifetime trajectories of vigorous PA (recalled at ages 18, 25, 50; prospectively assessed at baseline, and 3 and 6 years later). Hierarchical generalized linear mixed models examined the prospective association between optimism, cynical hostility, and vigorous PA over 6 years. Models adjusted for baseline sociodemographic variables, psychosocial characteristics, and health conditions and behaviors. Vigorous PA rates were highest for most optimistic women, but fell for all women by approximately 60% between age 50 and study baseline. In adjusted models from baseline through year 6, most vs. least optimistic women were 15% more likely to exercise vigorously (p < 0.001). Cynical hostility was not associated with lower odds of longitudinal vigorous PA after adjustment. Results did not differ by race/ethnicity or socioeconomic status. Higher optimism is associated with maintaining vigorous PA over time in post-menopausal women, and may protect women's health over the lifespan