Sensitization of renal carcinoma cells to TRAIL-induced apoptosis by rocaglamide and analogs

Rocaglamide has been reported to sensitize several cell types to TRAIL-induced apoptosis. In recent years, advances in synthetic techniques have led to generation of novel rocaglamide analogs. However, these have not been extensively analyzed as TRAIL sensitizers, particularly in TRAIL-resistant renal cell carcinoma cells. Evaluation of rocaglamide and analogs identified 29 compounds that are able to sensitize TRAIL-resistant ACHN cells to TRAIL-induced, caspase-dependent apoptosis with sub-µM potency which correlated with their potency as protein synthesis inhibitors and with loss of cFLIP protein in the same cells. Rocaglamide alone induced cell cycle arrest, but not apoptosis. Rocaglates averaged 4–5-fold higher potency as TRAIL sensitizers than as protein synthesis inhibitors suggesting a potential window for maximizing TRAIL sensitization while minimizing effects of general protein synthesis inhibition. A wide range of other rocaglate effects (e.g. on JNK or RAF-MEK-ERK signaling, death receptor levels, ROS, ER stress, eIF4E phosphorylation) were assessed, but did not contribute to TRAIL sensitization. Other than a rapid loss of MCL-1, rocaglates had minimal effects on mitochondrial apoptotic pathway proteins. The identification of structurally diverse/mechanistically similar TRAIL sensitizing rocaglates provides insights into both rocaglate structure and function and potential further development for use in RCC-directed combination therapy.This project has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. This research was supported [in part] by the Intramural Research Program of NIH, Frederick. National Lab, Center for Cancer Research. Research performed at Boston University was supported in part by NIH R35 GM118173. Work at the BU-CMD is supported by R24 GM111625. (HHSN261200800001E - National Cancer Institute, National Institutes of Health; Intramural Research Program of NIH, Frederick. National Lab, Center for Cancer Research; R35 GM118173 - NIH; R24 GM111625)Published versio

Twitching motility among pathogenic Xylella fastidiosa isolates and the influence of bovine serum albumin on twitching-dependent colony fringe morphology

Fourteen Xylella fastidiosa isolates from grapevines exhibiting Pierce's disease symptoms in California, Texas, and South Carolina were examined for type IV pilus-mediated twitching motility, a phenotype previously observed in a Temecula isolate from California. All isolates except one from South Carolina (SC 19A97) exhibited colonies with a peripheral fringe on PW agar, a feature indicative of twitching motility; however, when individual cells of SC 19A97 were examined at higher magnifications twitching motility was observed. The presence and width of colony peripheral fringes were related to the amount of bovine serum albumin (BSA) present in the medium; no or low levels of BSA (0-1.8 g L−1) permitted development of the widest fringe, whereas higher levels (3.5-6.0 g L−1) severely limited, and in many instances prevented, peripheral fringe development. The growth rate of the wild-type Temecula isolate in PW broth with different concentrations of BSA was similar for all tested concentrations of BSA; however, growth was significantly reduced in medium without BS

Non-Emergency Medical Transportation Needs of Middle-Aged and Older Adults: A Rural-Urban Comparison in Delaware, USA.

Background: Older adults in rural areas have unique transportation barriers to accessing medical care, which include a lack of mass transit options and considerable distances to health-related services. This study contrasts non-emergency medical transportation (NEMT) service utilization patterns and associated costs for Medicaid middle-aged and older adults in rural versus urban areas. Methods: Data were analyzed from 39,194 NEMT users of LogistiCare-brokered services in Delaware residing in rural (68.3%) and urban (30.9%) areas. Multivariable logistic analyses compared trip characteristics by rurality designation. Results: Rural (37.2%) and urban (41.2%) participants used services more frequently for dialysis than for any other medical concern. Older age and personal accompaniment were more common and wheel chair use was less common for rural trips. The mean cost per trip was greater for rural users (difference of $2910 per trip), which was attributed to the greater distance per trip in rural areas. Conclusions: Among a sample who were eligible for subsidized NEMT and who utilized this service, rural trips tended to be longer and, therefore, higher in cost. Over 50% of trips were made for dialysis highlighting the need to address prevention and, potentially, health service improvements for rural dialysis patients

Variation in Coral Thermotolerance Across a Pollution Gradient Erodes as Coral Symbionts Shift to More Heat-Tolerant Genera

Phenotypic plasticity is one mechanism whereby species may cope with stressful environmental changes associated with climate change. Reef building corals present a good model for studying phenotypic plasticity because they have experienced rapid climate-driven declines in recent decades (within a single generation of many corals), often with differential survival among individuals during heat stress. Underlying differences in thermotolerance may be driven by differences in baseline levels of environmental stress, including pollution stress. To examine this possibility, acute heat stress experiments were conducted on Acropora hyacinthus from 10 sites around Tutuila, American Samoa with differing nutrient pollution impact. A threshold-based heat stress assay was conducted in 2014 and a ramp-hold based assay was conducted in 2019. Bleaching responses were measured by assessing color paling. Endosymbiont community composition was assessed at each site using quantitative PCR. RNA sequencing was used to compare differences in coral gene expression patterns prior to and during heat stress in 2019. In 2014, thermotolerance varied among sites, with polluted sites holding more thermotolerant corals. These differences in thermotolerance correlated with differences in symbiont communities, with higher proportions of heat-tolerant Durusdinium found in more polluted sites. By 2019, thermotolerance varied less among sites, with no clear trend by pollution level. This coincided with a shift toward Durusdinium across all sites, reducing symbiont community differences seen in 2014. While pollution and symbiont community no longer could explain variation in thermotolerance by 2019, gene expression patterns at baseline levels could be used to predict thermotolerance thresholds. These patterns suggest that the mechanisms underlying thermotolerance shifted between 2014 and 2019, though it is possible trends may have also been affected by methodological differences between heat stress assays. This study documents a shift in symbiont community over time and captures potential implications of that shift, including how it affects variation in thermotolerance among neighboring reefs. This work also highlights how gene expression patterns could help identify heat-tolerant corals in a future where most corals are dominated by Durusdinium and symbiont-driven thermotolerance has reached an upper limit

Do Precision Chemical Amendment Applications Impact Sodium Movement in Dryland Semiarid Saline Sodic Soils?

Expanding sodicity and salinity problems have placed many northern Great Plains (NGP) soils at the sustainability tipping point. This study assessed the impact of chemical restoration on water and salt transport in undisturbed soil columns collected from three hillslope model landscape positions. The backslope (Redfield), footslope (White Lake), and toeslope (Pierpont) soils had moderate (3.27 ± 0.59), high (7.3 ± 3.34), and very high (13.29 ± 3.2) sodium adsorption ratio (SARe) values, respectively. The soils were treated with KBr and one of four soil amendments (none, H2SO4, CaSO4, and CaCl2). The rapid movement of Br−through the columns suggested that bypass water flow occurred. In addition, a comparison with widely used salinity models (final EC = 0.8 × initial EC/pore volume [PV]) underestimated the leaching requirements by 69, 79, and 41% in the backslope, footslope, and toeslope soils. In the footslope soils with high SAR values, H2SO4 was more effective at promoting Na+leaching than gypsum or CaCl2. However, in back slope and toeslope soils with moderate and very high SAR values, the chemical amendments were not, and were equally effective at facilitating Na+ leaching, respectively. These findings suggest that chemical amendments should target treatments to problem areas, and that bypass flow can influence their effectiveness. The LOESS regression model suggested that the electrical conductivity (ECe)/SARe ratio was useful for assessing Na+ risks, and that to maintain a water flow rate of 1 mm h–1 in a soil with a SARe value of 1, an ECe value of ≥2 was required

Reporting guidelines for experimental research: A report from the experimental research section standards committee.

The standards committee of the Experimental Research section was charged with preparing a set of reporting guidelines for experimental research in political science. The committee defined its task as compiling a set of guidelines sufficient to enable the reader or reviewer to follow what the researcher had done and to assess the validity of the conclusions the researcher had drawn. Although the guidelines do request the reporting of some basic statistics, they do not attempt to weigh in on statistical controversies. Rather, they aim for something more modest but nevertheless crucial: to ensure that scholars clearly describe what it is they did at each step in their research and clearly report what their data show. In this paper, we discuss the rationale for reporting guidelines and the process used to formulate the specific guidelines we endorse. The guidelines themselves are included in Appendix 1

Facing the Facets: No Association Between Dispositional Mindfulness Facets and Positive Momentary Stress Responses During Active Stressors

Mindfulness has been associated with enhanced coping with stress. However, it remains unclear how dispositional mindfulness impacts the nature and valence of experiences during active stressors. Across 1,001 total participants, we used cardiovascular responses from the biopsychosocial model of challenge/threat to assess the degree to which individuals cared about a stressor in the moment and had a positive versus negative psychological experience. Although we found a small association between mindfulness—particularly the acting with awareness facet—and responses consistent with caring more about the stressor(i.e., greater task engagement), we found no evidence that mindfulness was associated with exhibiting a more positive psychological response (i.e., greater challenge)during the stressor. Despite no differences in the valence of momentary experiences as a function of mindfulness, individuals higher in mindfulness self-reported more positive experiences afterward. These findings suggest that dispositional mindfulness may benefit responses to active stressors only after they have passed

TetR-Based Gene Regulation Systems for Francisella tularensis

ABSTRACT There are a number of genetic tools available for studying Francisella tularensis , the etiological agent of tularemia; however, there is no effective inducible or repressible gene expression system. Here, we describe inducible and repressible gene expression systems for F. tularensis based on the Tet repressor, TetR. For the inducible system, a tet operator sequence was cloned into a modified F. tularensis groESL promoter sequence and carried in a plasmid that constitutively expressed TetR. To monitor regulation the luminescence operon, luxCDABE , was cloned under the hybrid Francisella tetracycline-regulated promoter ( FTRp ), and transcription was initiated with addition of anhydrotetracycline (ATc), which binds TetR and alleviates TetR association with tetO. Expression levels measured by luminescence correlated with ATc inducer concentrations ranging from 20 to 250 ng ml −1 . In the absence of ATc, luminescence was below the level of detection. The inducible system was also functional during the infection of J774A.1 macrophages, as determined by both luminescence and rescue of a mutant strain with an intracellular growth defect. The repressible system consists of FTRp regulated by a reverse TetR mutant (revTetR), TetR r1.7. Using this system with the lux reporter, the addition of ATc resulted in decreased luminescence, while in the absence of ATc the level of luminescence was not significantly different from that of a construct lacking TetR r1.7. Utilizing both systems, the essentiality of SecA, the protein translocase ATPase, was confirmed, establishing that they can effectively regulate gene expression. These two systems will be invaluable in exploring F. tularensis protein function

Size- and charge-dependent non-specific uptake of PEGylated nanoparticles by macrophages

The assessment of macrophage response to nanoparticles is a central component in the evaluation of new nanoparticle designs for future in vivo application. This work investigates which feature, nanoparticle size or charge, is more predictive of non-specific uptake of nanoparticles by macrophages. This was investigated by synthesizing a library of polymer-coated iron oxide micelles, spanning a range of 30–100 nm in diameter and −23 mV to +9 mV, and measuring internalization into macrophages in vitro. Nanoparticle size and charge both contributed towards non-specific uptake, but within the ranges investigated, size appears to be a more dominant predictor of uptake. Based on these results, a protease-responsive nanoparticle was synthesized, displaying a matrix metalloproteinase-9 (MMP-9)-cleavable polymeric corona. These nanoparticles are able to respond to MMP-9 activity through the shedding of 10–20 nm of hydrodynamic diameter. This MMP-9-triggered decrease in nanoparticle size also led to up to a six-fold decrease in nanoparticle internalization by macrophages and is observable by T2-weighted magnetic resonance imaging. These findings guide the design of imaging or therapeutic nanoparticles for in vivo targeting of macrophage activity in pathologic states