Scientific opinion on an application for renewal of authorisation for continued marketing of maize 1507 and derived food and feed submitted under Articles 11 and 23 of Regulation (EC) No 1829/2003 by Pioneer Overseas Corporation and Dow AgroSciences LLC

Following the submission of application EFSA‐GMO‐RX‐001 under Regulation (EC) No 1829/2003 from Pioneer Overseas Corporation and Dow Agrosciences LLC, the Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) was asked to deliver a scientific risk assessment on the data submitted in the frame of a renewal of authorisation application of the insect‐resistant and herbicide‐tolerant genetically modified (GM) maize 1507. The data package received in the frame of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, an updated bioinformatics analysis and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed this data package for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the frame of the original application. Under the assumption that the DNA sequence of the event in maize 1507 considered for renewal is identical to the corrected sequence of the originally assessed event, the GMO Panel concludes that no new hazards or modified exposure and no new scientific uncertainties were identified for the application for renewal that would change the conclusions of the original risk assessment on maize 1507 (EFSA, 2005b, 2009).

Biotechnological uses of RNAi in plants: risk assessment considerations

RNAi offers opportunities to generate new traits in genetically modified (GM) plants. Instead of expressing novel proteins, RNAi-based GM plants reduce target gene expression. Silencing of off-target genes may trigger unintended effects, and identifying these genes would facilitate risk assessment. However, using bioinformatics alone is not reliable, due to the lack of genomic data and insufficient knowledge of mechanisms governing mRNA-small (s)RNA interactions.

RNAi-based GM plants: food for thought for risk assessors

RNA interference (RNAi) is an emerging technology that offers new opportunities for the generation of new traits in genetically modified (GM) plants. Potential risks associated with RNAi-based GM plants and issues specific to their risk assessment were discussed during an international scientific workshop (June 2014) organized by the European Food Safety Authority (EFSA). Selected key outcomes of the workshop are reported here.

A randomized clinical trial of Cogmed Working Memory Training in school-age children with ADHD: a replication in a diverse sample using a control condition

BACKGROUND

Cogmed Working Memory Training (CWMT) has received considerable attention as a promising intervention for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) in children. At the same time, methodological weaknesses in previous clinical trials call into question reported efficacy of CWMT. In particular, lack of equivalence in key aspects of CWMT (i.e., contingent reinforcement, time-on-task with computer training, parent-child interactions, supportive coaching) between CWMT and placebo versions of CWMT used in previous trials may account for the beneficial outcomes favoring CWMT.

METHODS

Eighty-five 7- to 11-year old school-age children with ADHD (66 male; 78%) were randomized to either standard CWMT (CWMT Active) or a well-controlled CWMT placebo condition (CWMT Placebo) and evaluated before and 3 weeks after treatment. Dependent measures included parent and teacher ratings of ADHD symptoms; objective measures of attention, activity level, and impulsivity; and psychometric indices of working memory and academic achievement (Clinical trial title: Combined cognitive remediation and behavioral intervention for the treatment of Attention-Deficit/Hyperactivity Disorder; http://clinicaltrials.gov/ct2/show/NCT01137318).

RESULTS

CWMT Active participants demonstrated significantly greater improvements in verbal and nonverbal working memory storage, but evidenced no discernible gains in working memory storage plus processing/manipulation. In addition, no treatment group differences were observed for any other outcome measures.

CONCLUSIONS

When a more rigorous comparison condition is utilized, CWMT demonstrates effects on certain aspects of working memory in children with ADHD; however, CWMT does not appear to foster treatment generalization to other domains of functioning. As such, CWMT should not be considered a viable treatment for children with ADHD.

The hybrid four-CBS-domain KINβγ subunit functions as the canonical γ subunit of the plant energy sensor SnRK1

The AMPK/SNF1/SnRK1 protein kinases are a family of ancient and highly conserved eukaryotic energy sensors that function as heterotrimeric complexes. These typically comprise catalytic α subunits and regulatory β and γ subunits, the latter function as the energy-sensing modules of animal AMPK through adenosine nucleotide binding. The ability to monitor accurately and adapt to changing environmental conditions and energy supply is essential for optimal plant growth and survival, but mechanistic insight in the plant SnRK1 function is still limited. In addition to a family of γ-like proteins, plants also encode a hybrid βγ protein that combines the Four-Cystathionine β-synthase (CBS)-domain (FCD) structure in γ subunits with a glycogen-binding domain (GBD), typically found in β subunits. We used integrated functional analyses by ectopic SnRK1 complex reconstitution, yeast mutant complementation, in-depth phylogenetic reconstruction, and a seedling starvation assay to show that only the hybrid KINβγ protein that recruited the GBD around the emergence of the green chloroplast-containing plants, acts as the canonical γ subunit required for heterotrimeric complex formation. Mutagenesis and truncation analysis further show that complex interaction in plant cells and γ subunit function in yeast depend on both a highly conserved FCD and a pre-CBS domain, but not the GBD. In addition to novel insight into canonical AMPK/SNF/SnRK1 γ subunit function, regulation and evolution, we provide a new classification of plant FCD genes as a convenient and reliable tool to predict regulatory partners for the SnRK1 energy sensor and novel FCD gene functions.

The AMPK/SNF1/SnRK1 fuel gauge and energy regulator: structure, function and regulation

All life forms on earth require a continuous input and monitoring of carbon and energy supplies. The AMP-activated kinase (AMPK)/sucrose non-fermenting1 (SNF1)/Snf1-related kinase1 (SnRK1) protein kinases are evolutionarily conserved metabolic sensors found in all eukaryotic organisms from simple unicellular fungi (yeast SNF1) to animals (AMPK) and plants (SnRK1). Activated by starvation and energy-depleting stress conditions, they enable energy homeostasis and survival by up-regulating energy-conserving and energy-producing catabolic processes, and by limiting energy-consuming anabolic metabolism. In addition, they control normal growth and development as well as metabolic homeostasis at the organismal level. As such, the AMPK/SNF1/SnRK1 kinases act in concert with other central signaling components to control carbohydrate uptake and metabolism, fatty acid and lipid biosynthesis and the storage of carbon energy reserves. Moreover, they have a tremendous impact on developmental processes that are triggered by environmental changes such as nutrient depletion or stress. Although intensive research by many groups has partly unveiled the factors that regulate AMPK/SNF1/SnRK1 kinase activity as well as the pathways and substrates they control, several fundamental issues still await to be clarified. In this review, we will highlight these issues and focus on the structure, function and regulation of the AMPK/SNF1/SnRK1 kinases.

A single active trehalose-6-P synthase (TPS) and a family of putative regulatory TPS-like proteins in Arabidopsis

Higher plants typically do not produce trehalose in large amounts, but their genome sequences reveal large families of putative trehalose metabolism enzymes. An important regulatory role in plant growth and development is also emerging for the metabolic intermediate trehalose-6-P (T6P). Here, we present an update on Arabidopsis trehalose metabolism and a resource for further detailed analyses. In addition, we provide evidence that Arabidopsis encodes a single trehalose-6-P synthase (TPS) next to a family of catalytically inactive TPS-like proteins that might fulfill specific regulatory functions in actively growing tissues.

Psoriasis patients generate increased serum levels of autoantibodies to tumor necrosis factor-alpha and interferon-alpha

BACKGROUND

It has been shown in experimental animal models that were extended to humans that during autoimmune conditions, the immune system generates beneficial autoantibody (auto Ab) response to a limited number of inflammatory mediators that drive the pathogenesis of the disease.

OBJECTIVE

To investigate the presence of auto Abs to cytokines and chemokines in psoriasis.

METHODS

Sera were obtained from patients with psoriasis (n=37), atopic dermatitis (AD) (n=18) and healthy volunteers (n=56). The titers of auto (Abs) to TNF-alpha, interferon-alpha (IFN-alpha), interleukin-17 (IL-17), and chemokines CCL2, CCL3 and CCL5 were determined using enzyme-linked immunosorbant assay. Neutralizing activities of high-titer auto Abs to TNF-alpha and IFN-alpha were determined using functional in vitro assays.

RESULTS

Highly significant increased titers of auto Abs to TNF-alpha and IFN-alpha were detected in patients with psoriasis compared with healthy subjects and patients with AD (mean titers more than fourfold). These auto Abs demonstrated some neutralizing activity in vitro, but their serum levels did not correlate with the intensity and duration of the disease and with phototherapy induced remissions. Significantly increased titers albeit to a lesser extent, of auto Abs to CCL3 were detected in AD.

CONCLUSIONS

Psoriasis patients produce markedly increased levels of auto Abs to TNF-alpha and IFN-alpha which are two of the key cytokines in this disorder. The presence of these auto Abs which possess some neutralizing activity in vitro, may be an epiphenomenon or might play a role in attempting to suppress the ongoing inflammatory process.

Extensive expression regulation and lack of heterologous enzymatic activity of the Class II trehalose metabolism proteins from Arabidopsis thaliana

Trehalose metabolism has profound effects on plant growth and metabolism, but the mechanisms involved are unclear. In Arabidopsis, 21 putative trehalose biosynthesis genes are classified in three subfamilies based on their similarity with yeast TPS1 (encoding a trehalose-6-phosphate synthase, TPS) or TPS2 (encoding a trehalose-6-phosphate phosphatase, TPP). Although TPS1 (Class I) and TPPA and TPPB (Class III) proteins have established TPS and TPP activity, respectively, the function of the Class II proteins (AtTPS5-AtTPS11) remains elusive. A complete set of promoter-beta-glucurinidase/green fluorescent protein reporters demonstrates their remarkably differential tissue-specific expression and responsiveness to carbon availability and hormones. Heterologous expression in yeast furthermore suggests that none of the encoded enzymes displays significant TPS or TPP activity, consistent with a regulatory rather than metabolic function for this remarkable class of proteins.