Functional analysis of a cinnamyl alcohol dehydrogenase involved in lignin biosynthesis in wheat

Cinnamyl alcohol dehydrogenase (CAD) catalyses the final step in the biosynthesis of monolignols. In the present study, a cDNA encoding a CAD was isolated from wheat, designated as TaCAD1. A genome-wide data mining in the wheat EST database revealed another 10 CAD-like homologues, namely TaCAD2 to TaCAD11. A phylogenetic analysis showed that TaCAD1 belonged to the bona fide CAD group involved in lignin synthesis. Two other putative CADs from the wheat genome (TaCAD2 and TaCAD4) also belonged to this group and were very close to TaCAD1, but lacked C-terminal domain, suggesting that they are pseudogenes. DNA gel blot analysis for the wheat genome showed two to three copies of CAD related to TaCAD1, but RNA gel blot analysis revealed only single band for TaCAD1, which was highly expressed in stem, with quite low expression in leaf and undetectable expression in root. The predicted three-dimension structure of TaCAD1 resembled that of AtCAD5, but two amino acid substitutions were identified in the substrate binding region. Recombinant TaCAD1 protein used coniferyl aldehyde as the most favoured substrate, also showed high efficiencies toward sinapyl and p-coumaryl aldehydes. TaCAD1 was an enzyme being pH-dependent and temperature-sensitive, and showing a typical random catalysing mechanism. At the milky stage of wheat, TaCAD1 mRNA abundance, protein level and enzyme activity in stem tissues were higher in a lodging-resistant cultivar (H4546) than in lodging-sensitive cultivar (C6001). These properties were correlated to the lignin contents and lodging indices of the two cultivars. These data suggest that TaCAD1 is the predominant CAD in wheat stem for lignin biosynthesis and is critical for lodging resistance

Molecular behaviour of phenol in zeolite Beta catalysts as a function of acid site presence: a quasielastic neutron scattering and molecular dynamics simulation study

Quasielastic neutron scattering (QENS) experiments complemented by classical molecular dynamics (MD) simulations at 393–443 K were employed in a study of the mobility and interactions of phenol in acidic zeolite H-Beta, to understand systems relevant to potential routes for the depolymerization and hydrodeoxygenation of lignin. QENS experiments observed isotropic phenol rotation with a fraction of static molecules, yielding rotational diffusion coefficients between 2.60 × 1010 and 3.33 × 1010 s−1 and an activation energy of rotation of 7.2 kJ mol−1. The MD simulations of phenol in the acidic and all-silica zeolite corroborate the experimental results, where molecules strongly adsorbed to the acidic sites behave as an immobile fraction with minimal contribution to the rotational diffusion, and the mobile molecules yield similar rotational diffusion coefficients to experiment. Translational diffusion is too slow to be detected in the instrumental time window of the QENS experiments, which is supported by MD-calculated activation energies of translation larger than 25 kJ mol−1. The study illustrates the effect of active sites in potential catalyst structures on the dynamical behaviour of molecules relevant to biomass conversion

Amyloid-β nanotubes are associated with prion protein-dependent synaptotoxicity

Growing evidence suggests water-soluble, non-fibrillar forms of amyloid-β protein (Aβ) have important roles in Alzheimer's disease with toxicities mimicked by synthetic Aβ1-42. However, no defined toxic structures acting via specific receptors have been identified and roles of proposed receptors, such as prion protein (PrP), remain controversial. Here we quantify binding to PrP of Aβ1-42 after different durations of aggregation. We show PrP-binding and PrP-dependent inhibition of long-term potentiation (LTP) correlate with the presence of protofibrils. Globular oligomers bind less avidly to PrP and do not inhibit LTP, whereas fibrils inhibit LTP in a PrP-independent manner. That only certain transient Aβ assemblies cause PrP-dependent toxicity explains conflicting reports regarding the involvement of PrP in Aβ-induced impairments. We show that these protofibrils contain a defined nanotubular structure with a previously unidentified triple helical conformation. Blocking the formation of Aβ nanotubes or their interaction with PrP might have a role in treatment of Alzheimer's disease

Value of Energy Storage for Grid Applications

This analysis evaluates several operational benefits of electricity storage, including load-leveling, spinning contingency reserves, and regulation reserves. Storage devices were simulated in a utility system in the western United States, and the operational costs of generation was compared to the same system without the added storage. This operational value of storage was estimated for devices of various sizes, providing different services, and with several sensitivities to fuel price and other factors. Overall, the results followed previous analyses that demonstrate relatively low value for load-leveling but greater value for provision of reserve services. The value was estimated by taking the difference in operational costs between cases with and without energy storage and represents the operational cost savings from deploying storage by a traditional vertically integrated utility. The analysis also estimated the potential revenues derived from a merchant storage plant in a restructured market, based on marginal system prices. Due to suppression of on-/off-peak price differentials and incomplete capture of system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit provided to the system. This demonstrates some of the additional challenges for storage deployed in restructured energy markets

Development of a reactive stroma associated with prostatic intraepithelial neoplasia in EAF2 deficient mice

ELL-associated factor 2 (EAF2) is an androgen-responsive tumor suppressor frequently deleted in advanced prostate cancer that functions as a transcription elongation factor of RNA Pol II through interaction with the ELL family proteins. EAF2 knockout mice on a 129P2/OLA-C57BL/6J background developed late-onset lung adenocarcinoma, hepatocellular carcinoma, B-cell lymphoma and high-grade prostatic intraepithelial neoplasia. In order to further characterize the role of EAF2 in the development of prostatic defects, the effects of EAF2 loss were compared in different murine strains. In the current study, aged EAF2-/- mice on both the C57BL/6J and FVB/NJ backgrounds exhibited mPIN lesions as previously reported on a 129P2/OLA-C57BL/6J background. In contrast to the 129P2/OLA-C57BL/6J mixed genetic background, the mPIN lesions in C57BL/6J and FVB/NJ EAF2-/- mice were associated with stromal defects characteristic of a reactive stroma and a statistically significant increase in prostate microvessel density. Stromal inflammation and increased microvessel density was evident in EAF2-deficient mice on a pure C57BL/6J background at an early age and preceded the development of the histologic epithelial hyperplasia and neoplasia found in the prostates of older EAF2 -/- animals. Mice deficient in EAF2 had an increased recovery rate and a decreased overall response to the effects of androgen deprivation. EAF2 expression in human cancer was significantly down-regulated and microvessel density was significantly increased compared to matched normal prostate tissue; furthermore EAF2 expression was negatively correlated with microvessel density. These results suggest that the EAF2 knockout mouse on the C57BL/6J and FVB/NJ genetic backgrounds provides a model of PIN lesions associated with an altered prostate microvasculature and reactive stromal compartment corresponding to that reported in human prostate tumors. © 2013 Pascal et al

The PKR-binding domain of adenovirus VA RNAI exists as a mixture of two functionally non-equivalent structures

VA RNAI is a non-coding adenoviral transcript that counteracts the host cell anti-viral defenses such as immune responses mediated via PKR. We investigated potential alternate secondary structure conformations within the PKR-binding domain of VA RNAI using site-directed mutagenesis, RNA UV-melting analysis and enzymatic RNA secondary structure probing. The latter data clearly indicated that the wild-type VA RNAI apical stem can adopt two different conformations and that it exists as a mixed population of these two structures. In contrast, in two sequence variants we designed to eliminate one of the possible structures, while leaving the other intact, each formed a unique secondary structure. This clarification of the apical stem pairing also suggests a small alteration to the apical stem–loop secondary structure. The relative ability of the two apical stem conformations to bind PKR and inhibit kinase activity was measured by isothermal titration calorimetry and PKR autophosphorylation inhibition assay. We found that the two sequence variants displayed markedly different activities, with one being a significantly poorer binder and inhibitor of PKR. Whether the presence of the VA RNAI conformation with reduced PKR inhibitory activity is directly beneficial to the virus in the cell for some other function requires further investigation

Barriers to colorectal cancer screening in community health centers: A qualitative study

<p>Abstract</p> <p>Background</p> <p>Colorectal cancer screening rates are low among disadvantaged patients; few studies have explored barriers to screening in community health centers. The purpose of this study was to describe barriers to/facilitators of colorectal cancer screening among diverse patients served by community health centers.</p> <p>Methods</p> <p>We identified twenty-three outpatients who were eligible for colorectal cancer screening and their 10 primary care physicians. Using in-depth semi-structured interviews, we asked patients to describe factors influencing their screening decisions. For each unscreened patient, we asked his or her physician to describe barriers to screening. We conducted patient interviews in English (n = 8), Spanish (n = 2), Portuguese (n = 5), Portuguese Creole (n = 1), and Haitian Creole (n = 7). We audiotaped and transcribed the interviews, and then identified major themes in the interviews.</p> <p>Results</p> <p>Four themes emerged: 1) Unscreened patients cited lack of trust in doctors as a barrier to screening whereas few physicians identified this barrier; 2) Unscreened patients identified lack of symptoms as the reason they had not been screened; 3) A doctor's recommendation, or lack thereof, significantly influenced patients' decisions to be screened; 4) Patients, but not their physicians, cited fatalistic views about cancer as a barrier. Conversely, physicians identified competing priorities, such as psychosocial stressors or comorbid medical illness, as barriers to screening. In this culturally diverse group of patients seen at community health centers, similar barriers to screening were reported by patients of different backgrounds, but physicians perceived other factors as more important.</p> <p>Conclusion</p> <p>Further study of these barriers is warranted.</p

Rucaparib for patients with platinum-sensitive, recurrent ovarian carcinoma (ARIEL3): post-progression outcomes and updated safety results from a randomised, placebo-controlled, phase 3 trial

BACKGROUND: In ARIEL3, rucaparib maintenance treatment significantly improved progression-free survival versus placebo. Here, we report prespecified, investigator-assessed, exploratory post-progression endpoints and updated safety data. METHODS: In this ongoing (enrolment complete) randomised, placebo-controlled, phase 3 trial, patients aged 18 years or older who had platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube carcinoma and an Eastern Cooperative Oncology Group performance status of 0 or 1 who had received at least two previous platinum-based chemotherapy regimens and responded to their last platinum-based regimen were randomly assigned (2:1) to oral rucaparib (600 mg twice daily) or placebo in 28-day cycles using a computer-generated sequence (block size of six with stratification based on homologous recombination repair gene mutation status, progression-free interval following penultimate platinum-based regimen, and best response to most recent platinum-based regimen). Patients, investigators, site staff, assessors, and the funder were masked to assignments. The primary endpoint of investigator-assessed progression-free survival has been previously reported. Prespecified, exploratory outcomes of chemotherapy-free interval (CFI), time to start of first subsequent therapy (TFST), time to disease progression on subsequent therapy or death (PFS2), and time to start of second subsequent therapy (TSST) and updated safety were analysed (visit cutoff Dec 31, 2017). Efficacy analyses were done in all patients randomised to three nested cohorts: patients with BRCA mutations, patients with homologous recombination deficiencies, and the intention-to-treat population. Safety analyses included all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT01968213. FINDINGS: Between April 7, 2014, and July 19, 2016, 564 patients were enrolled and randomly assigned to rucaparib (n=375) or placebo (n=189). Median follow-up was 28·1 months (IQR 22·0-33·6). In the intention-to-treat population, median CFI was 14·3 months (95% CI 13·0-17·4) in the rucaparib group versus 8·8 months (8·0-10·3) in the placebo group (hazard ratio [HR] 0·43 [95% CI 0·35-0·53]; p<0·0001), median TFST was 12·4 months (11·1-15·2) versus 7·2 months (6·4-8·6; HR 0·43 [0·35-0·52]; p<0·0001), median PFS2 was 21·0 months (18·9-23·6) versus 16·5 months (15·2-18·4; HR 0·66 [0·53-0·82]; p=0·0002), and median TSST was 22·4 months (19·1-24·5) versus 17·3 months (14·9-19·4; HR 0·68 [0·54-0·85]; p=0·0007). CFI, TFST, PFS2, and TSST were also significantly longer with rucaparib than placebo in the BRCA-mutant and homologous recombination-deficient cohorts. The most frequent treatment-emergent adverse event of grade 3 or higher was anaemia or decreased haemoglobin (80 [22%] patients in the rucaparib group vs one [1%] patient in the placebo group). Serious treatment-emergent adverse events were reported in 83 (22%) patients in the rucaparib group and 20 (11%) patients in the placebo group. Two treatment-related deaths have been previously reported in this trial; there were no new treatment-related deaths. INTERPRETATION: In these exploratory analyses over a median follow-up of more than 2 years, rucaparib maintenance treatment led to a clinically meaningful delay in starting subsequent therapy and provided lasting clinical benefits versus placebo in all three analysis cohorts. Updated safety data were consistent with previous reports. FUNDING: Clovis Oncology

Rucaparib maintenance treatment for recurrent ovarian carcinoma after response to platinum therapy (ARIEL3): a randomised, double-blind, placebo-controlled, phase 3 trial

Background: Rucaparib, a poly(ADP-ribose) polymerase inhibitor, has anticancer activity in recurrent ovarian carcinoma harbouring a BRCA mutation or high percentage of genome-wide loss of heterozygosity. In this trial we assessed rucaparib versus placebo after response to second-line or later platinum-based chemotherapy in patients with high-grade, recurrent, platinum-sensitive ovarian carcinoma. Methods: In this randomised, double-blind, placebo-controlled, phase 3 trial, we recruited patients from 87 hospitals and cancer centres across 11 countries. Eligible patients were aged 18 years or older, had a platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube carcinoma, had received at least two previous platinum-based chemotherapy regimens, had achieved complete or partial response to their last platinum-based regimen, had a cancer antigen 125 concentration of less than the upper limit of normal, had a performance status of 0–1, and had adequate organ function. Patients were ineligible if they had symptomatic or untreated central nervous system metastases, had received anticancer therapy 14 days or fewer before starting the study, or had received previous treatment with a poly(ADP-ribose) polymerase inhibitor. We randomly allocated patients 2:1 to receive oral rucaparib 600 mg twice daily or placebo in 28 day cycles using a computer-generated sequence (block size of six, stratified by homologous recombination repair gene mutation status, progression-free interval after the penultimate platinum-based regimen, and best response to the most recent platinum-based regimen). Patients, investigators, site staff, assessors, and the funder were masked to assignments. The primary outcome was investigator-assessed progression-free survival evaluated with use of an ordered step-down procedure for three nested cohorts: patients with BRCA mutations (carcinoma associated with deleterious germline or somatic BRCA mutations), patients with homologous recombination deficiencies (BRCA mutant or BRCA wild-type and high loss of heterozygosity), and the intention-to-treat population, assessed at screening and every 12 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01968213; enrolment is complete. Findings: Between April 7, 2014, and July 19, 2016, we randomly allocated 564 patients: 375 (66%) to rucaparib and 189 (34%) to placebo. Median progression-free survival in patients with a BRCA-mutant carcinoma was 16·6 months (95% CI 13·4–22·9; 130 [35%] patients) in the rucaparib group versus 5·4 months (3·4–6·7; 66 [35%] patients) in the placebo group (hazard ratio 0·23 [95% CI 0·16–0·34]; p&lt;0·0001). In patients with a homologous recombination deficient carcinoma (236 [63%] vs 118 [62%]), it was 13·6 months (10·9–16·2) versus 5·4 months (5·1–5·6; 0·32 [0·24–0·42]; p&lt;0·0001). In the intention-to-treat population, it was 10·8 months (8·3–11·4) versus 5·4 months (5·3–5·5; 0·36 [0·30–0·45]; p&lt;0·0001). Treatment-emergent adverse events of grade 3 or higher in the safety population (372 [99%] patients in the rucaparib group vs 189 [100%] in the placebo group) were reported in 209 (56%) patients in the rucaparib group versus 28 (15%) in the placebo group, the most common of which were anaemia or decreased haemoglobin concentration (70 [19%] vs one [1%]) and increased alanine or aspartate aminotransferase concentration (39 [10%] vs none). Interpretation: Across all primary analysis groups, rucaparib significantly improved progression-free survival in patients with platinum-sensitive ovarian cancer who had achieved a response to platinum-based chemotherapy. ARIEL3 provides further evidence that use of a poly(ADP-ribose) polymerase inhibitor in the maintenance treatment setting versus placebo could be considered a new standard of care for women with platinum-sensitive ovarian cancer following a complete or partial response to second-line or later platinum-based chemotherapy. Funding: Clovis Oncology