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Anti-inflammatory, immuno-modulatory, and anti-proliferative effects of 5-mer Oligogalacturonides (OG DP5) from citrus pectin on different types of human cells. Perspectives for treatment of dermal diseases such as atopic dermatitis and psoriasis
No full textInternational audienceBackground: Oligogalacturonides (OG) are natural plant cell wall pectin-derived products with different degrees of polymerisation (DP) and methylation (M) (see Yu et al. 2022). Their effects as stimulators of plant defence are well documented and they are also known for their potent effects on human health.Purpose: Here, we investigated the anti-inflammatory effects of OG extracted from Citrus on different types of human cells and cell systems representative of several pathologies. Study design: Different concentrations of 5-mer OG (DP5) with different methylation degrees (M: 0, 5, 30 and 70) were tested on cultured human peripheral blood mononuclear cells (PBMC) to see if there were able to decrease LPS-induced IL-1β release. Then, different human cell combination stimulated by specific agonists representative of several pathologies were used to test the effect of the most active OG DP5M0 (0 methylation).Methods: IL-1β was monitored in the PBMC culture medium with ELISA and effects on bio-markers typical of pathologies were studied using the BioMAP Diversity PLUS® method (Eurofins, France).Results: DP5M0 dose-dependently reduced LPS-induced IL-1β release by cultured human peripheral blood mononuclear cells (PBMC). This was not observed for DP5M30 or DP5M70. DP5M0 was also more efficient than prednisolone when tested on 12 different human cell systems representative of known pathologies (BioMAP systems). The T BioMAP system, which consists in an equal combination of B cells and PBMC, shows the best response sensitivity to DP5M0. This latter induces a dose-dependent decrease of the biomarkers of inflammation and of those of immune responses (IL-6, IL-8, IL-2, IL-17A, IL-17F and TNF-α).Conclusion: In view that all these cytokines are involved in keratinocytes proliferation and differentiation, this model system fits with a possible beneficial effect of DP5M0 on atopic dermatitis and psoriasis. DP5M0 also showed anti-proliferative properties in 5 different cell systems. The comparison of the BioMAP profiles of DP5M0 and anti-inflammatory products prednisolone and diclofenac indicates that their modes of action are different. These data argue for a possible use of DP5M0 for treatments of psoriasis diseases as alternative strategy to other developed medicines when the patients do not tolerate them
Structural and functional characterization of nitric oxide synthases (NOS) of Klebsormidium nitens
No full textNational audienceNitric oxide (NO) is a mediator of numerous physiological processes, playing a central role in a varietyof organisms. In plants, NO is involved in responses to biotic and abiotic stress, stomatal closure,photomorphogenesis, leaf senescence, flowering and fertilization. In animals, NO synthesis is mainlycarried out by Nitric Oxide Synthases (NOS), which catalyse the oxidation of L-Arg to L-citrulline andNO. Although many land plant genomes have been sequenced, no NOS-like sequences have beenidentified. However, NOS-like sequences have been identified in some twenty species ofphotosynthetic organisms, including the green alga Klebsormidium nitens (Streptophytes) which canbe seen as a model for the study of plant adaptation to terrestrial life.The aim of this thesis is to confirm the presence of transcripts corresponding to the NOS-like genessequenced in klebsormidium nitens. And to characterize the different NOS-like produced.Also, this thesis aims to study the role of NO in plants according to its production using as a model anenzyme regulated by S-nitrosation, the fructose-1-6-bisphosphatase in K. nitens.This thesis will further our knowledge of the evolution of sources of NO production and its role inplants, as well as generating new insights for the biology of algae
Compréhension des réponses microbiennes à des perturbations de leur environnement : application au développement de procédés de maitrise de micro-organismes
No full textImpact of processing and storage on citrus fiber functionality: Insights from spectroscopic techniques
No full textInternational audienceTo deliver their functionality when used in applications, citrus fibers need to be rehydrated. Factors such as chemical composition, structural organization as well as chemical surface composition are known to influence this functionality. Processing and storage conditions can affect these parameters, making it challenging to maintain stable functionality. This study used Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to evaluate the effects of preparation and storage on citrus fibers. Samples dried at different scales and stored for 360 days under room and accelerated conditions were assessed for water holding capacity (WHC), water swelling capacity (WSC), and gel rigidity (G′). The results showed a decline in WHC, WSC, and G′ over time, confirming that aging negatively impacts moisture retention, particularly under higher water content or temperature. Drying scale had no effect on chemical composition or structure, but changes in the elemental surface composition of carbon and oxygen were noted. While prolonged storage altered the polysaccharides' chemical composition and structure, leading to functionality loss, XPS analysis revealed no changes in surface composition. Loss of functionality cannot be explained by chemical surface composition modifications
Organiser la fabrique démocratique des transitions : l'exemple du Collectif Nourrir
No full textCe numéro fait suite au carrefour de l'innovation agronomique dédié aux innovations organisationnelles pour la transition agroécologique et des systèmes agri-alimentaires durables qui s'est déroulée en mars 2024 à VetSup Agro à Lembdes.National audienceThe changes needed in agri-food systems to meet the challenges of climate change and the erosion of biodiversity require both organizational and technological innovations. The experience of the Collectif Nourrir, which gathers 54 civil society organizations working on agricultural and food issues, provides some initial insights into the principles, barriers and levers that need to be identified in order to initiate a process of organizational innovation.Les transformations nécessaires dans les systèmes agro-alimentaires pour relever les défis climatiques et d'érosion de la biodiversité doivent autant mobiliser des innovations organisationnelles que des innovations technologiques. L'expérience du Collectif Nourrir qui réunit 54 organisations de la société civile sur les enjeux agricoles et alimentaires apporte de premiers éléments quant aux principes, verrous et leviers à identifier pour engager un processus d'innovation organisationnelle
Transmettre et apprendre dans des espaces hybrides : entre travail et formation
No full textInternational audienceL’ambition de ce dossier thématique est de placer les pratiques de la formation professionnelle sous le regard d’approches orientées par l’activité et son réseau conceptuel. Ceci inclut l’ergonomie, mais pas seulement. D’autres disciplines, telles que la didactique professionnelle, les didactiques disciplinaires, les sciences de l’éducation ou les sciences du langage sont aujourd’hui régulièrement sollicitées pour penser les rapports entre travail et formation et adopter les questionnements suivants : comment l’activité de travail peut-elle constituer un objet de transmission ? Comment devient-elle apprenable ? À travers quels dispositifs et quelles médiations la rencontre entre le travail et la formation est-elle susceptible de faire sens pour les acteurs
Machine Learning and Artificial Intelligence for Sustainable Cropping Systems
No full textNational audienceThe use of Machine Learning and Artificial Intelligence techniques to promote sustainable management of cropping systems is at the core of this work. The goal is to develop an innovative approach by combining these digital technologies with simple sensors using visible imaging to monitor the nitrogen status of cereal crops in cereal/legume intercropping systems. Currently, available tools for assessing these needs are clamps or chlorophyll meters (SPAD, N-Tester), which rely on optical measurements—indirect measures of the nitrogen content of plants. These contact measurements with the leaves are time-consuming for dynamic field monitoring. This has led to the exploration of visible imaging, which is technically simpler but requires image segmentation to identify the crop in order to assess its nitrogen status. This study relies on semantic segmentation with the DeepLabV3+ model, a Deep Learning technique
graft4dendrogram
No full textThis R code offers a function to add a new leaf to a dendrogram.The proposed algorithm find the best point to graft the new leaf and perform the graft.A demo and an evaluation test codes are provided
P25-06 PackSafe: Integrated chemical safety assessment of Food Contact Articles (ANR-21-CE21-0004 project: 2022–2025)
No full textInternational audienceThe environmental impact of food packaging has become a major concern. In line with the directive (EU) N°2019/904, the French law (N°2020-105) on circular economy enforces manufacturers to lighten Food Contact Articles (FCA), recycle and/or reuse them. These new FCA should be as safe as virgin materials, but some scientific articles have demonstrated a greater release of chemical contaminants in food. Contaminants such as Non-Intentionally Added Substances (NIAS) are represented by impurities, decomposition or reaction products and substances resulting from recycling. They are often unpredictable, difficult to identify, to quantify and their toxicity is not always assessed. As consumers are exposed to NIAS through foodstuffs, the health risk must also be assessed (European plastic Regulation (EU) N°10/2011).The French project “PACKSAFE” proposes a relevant approach combining bioassays, analytical and physicochemical analyses on FCA extracts to consider all the substances able to migrate from packaging to food. The first step of “PACKSAFE” is to optimize a specific protocol of extraction regarding representative FCA extracts (PET, PE, HDPE, PP, PS, paper-board), relevant in vitro bioassays to identify genotoxic effects or endocrine activities. Spiking methodologies are performed to determine the specificity and the biological detection level of the selected bioassays.Forty-one samples were selected from the French market. Among these samples, 34% were recycled, 41% were coloured or printed and 61% had already been in contact with food.The protocol of sample preparation in a biocompatible solvent was optimised by using dimethyl sulfoxide (DMSO). This protocol, applied on a reference solution containing 93 substances of known concentrations representing the widest possible range of physic-chemical properties that can be found in FCA (polarity, molecular mass, Kovatz index, H donor/acceptor), gave a median recovery rate of 85%.In terms of genotoxicity, in the mini-Ames test, 2 extracts were positive. With the MultiFlow® DNA damage assay, only one extract was positive for clastogenic activity with the biomarkers γH2AX and p53. In the micronucleus assay, 4 extracts were positive in vitro. Positive extracts are on the way to be analysed using fractionation methodologies to try to identify the active substance(s).Concerning endocrine disruption, 6 extracts were positive in the ER reporter gene assay and 2 in the AR reporter gene assay. In the steroidogenesis test, several extracts were active increasing the estradiol synthesis.The innovative nature of this project is to use, in parallel, chemical signatures of extracts and robust bioassays to generate a database to facilitate decision-making and packaging security at different stages of their production life cycle. It will also generate data on the toxicity of new NIAS