Safety assessment of N-acetyl-L-threonine

ASPG and DAD1 are potential placental-derived biomarkers for ASD-like symptom severity levels in male/female offspring

INTRODUCTION

An early evaluating system for autism spectrum disorder (ASD) severity is crucial. Questionnaire survey is challenging for accurately assessing the severity levels for ASD in children.

METHODS

Offspring with ASD-like phenotypes were induced by treating pregnant mice with Poly (I:C) at GD12.5 and the placentae corresponding to the offspring were obtained by caesarean. The autism severity composite score (ASCS) for offspring was calculated through behavioral tests. HE staining and immunohistochemistry were used to observe the morphology of placenta. Candidate biomarkers were identified by weighted protein co-expression network analysis (WPCNA) combined with machine learning and further validated by ELISA. Sperman's was used to analyze the correlation between biomarkers and metabolome.

RESULTS

The placental weight and mean vascular area of male offspring with ASD-like phenotypes were significantly decreased compared with typical mice. According to the WPCNA, four modules were identified and significantly correlated with ASCS of offspring. Two biomarkers (ASPG and DAD1) with high correlation with ASCS in offspring were identified.

DISCUSSION

VEGF pathway may contribute to sexual dimorphism in placental morphology within mice with ASD-like phenotypes in term. The placental ASPG and DAD1 levels could reflect ASD-like symptom severity levels in male/female mice offspring.

Assessment of genetically modified oilseed rape 73496 for food and feed uses, under Regulation (EC) No 1829/2003 (application EFSA-GMO-NL-2012-109)

Oilseed rape 73496 was developed to confer tolerance to the herbicidal active substance glyphosate through the expression of the glyphosate acetyltransferase protein GAT4621. The molecular characterisation data and bioinformatic analyses identify no issues requiring food/feed safety assessment. None of the identified differences between oilseed rape 73496 and its conventional counterpart in the agronomic/phenotypic endpoints tested needs further assessment. Differences identified in seed composition of oilseed rape 73496 as compared to its conventional counterpart raise no safety and nutritional concerns in the context of the scope of this application. No safety concerns are identified regarding toxicity and allergenicity of the GAT4621 protein as expressed in oilseed rape 73496. No evidence is found that the genetic modification would change the overall allergenicity of oilseed rape 73496. Based on the outcome of the comparative and nutritional assessments, the consumption of oilseed rape 73496 does not represent any nutritional concern, in the context of the scope of this application. The implementation of a post-market monitoring plan is recommended to confirm the predicted consumption data and to verify that the conditions of use are those considered during the pre-market risk assessment. In the case of accidental release of viable oilseed rape 73496 seeds into the environment, oilseed rape 73496 would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of oilseed rape 73496. The GMO Panel concludes that oilseed rape 73496, as described in this application, is as safe as its conventional counterpart and the non-genetically modified oilseed rape reference varieties tested with respect to potential effects on human and animal health and the environment.

Human dietary exposure assessment to newly expressed proteins in GM foods

EFSA carries out the risk assessment of genetically modified organisms (GMOs) submitted under Regulation (EC) 1829/2003 and Regulation (EU) 503/2013. Dietary exposure is an essential element of the risk assessment on genetically modified (GM) foods. Dietary exposure estimations should cover average and high consumers across all the different age classes and special population groups and identify and consider particular consumer groups with expected higher exposure. This EFSA statement provides guidance on how human dietary exposure to newly expressed proteins in GM foods should be estimated using a deterministic model that makes use of the available information. Summary statistics of consumption of foods containing, consisting of and produced from crops relevant for the assessment of GMO applications are available in the EFSA website together with different factors to convert the reported consumption of processed foods into raw primary commodities. Guidance is also provided on how concentration data of newly expressed proteins, typically determined in raw primary commodities, should be used (materials to be analysed, growth stage, descriptive statistics to be used, etc.). An overview of the different uncertainties linked to the dietary exposure estimations is provided, informing on the strengths and limitations of the assessment. The document also describes the information applicants need to provide on human dietary exposure to allow EFSA doing an appropriate evaluation of the assessment provided as part of the application dossiers.