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Development and Optimization of an RNA-Isolating Protocol for Mammalian Spermatozoa
No full textInternational audienceThe RNAs present in spermatozoa play a crucial role in reproduction and embryonic development. They represent a promising diagnostic tool for assessing male infertility. However, their extraction is challenging due to their low concentration and highly condensed chromatin structure, as well as the presence of numerous cellular contaminants. These challenges vary across species and require the development of an optimized and reliable isolation method to obtain high-quality RNAs, which is essential for further molecular analyses regarding the roles played by these RNAs. This study evaluated two RNA extraction methods for spermatozoa in humans and other mammals (dogs, stallions, and bulls): a standard method using the NucleoSpin RNA® II kit (Macherey-Nagel) and an optimized method that combined this kit with dithiothreitol and TRIzol™ pretreatment. In addition, the samples underwent pre-purification to eliminate somatic cells. The optimized method produced a significantly higher total RNA yield along with better purity, which was confirmed by the absence of the 18S and 28S ribosomal RNA peaks, indicating the absence of somatic cell contamination. Additionally, RT-PCR was performed to validate the presence of sperm-specific markers. The quality of the extracted RNAs was assessed by sequencing the mRNA encoding the human olfactory receptor OR1D2 and observing the resulting band on an agarose slab gel with a size corresponding to its entire open reading frame. By addressing long-standing challenges in sperm RNA isolation, our method provides an easy and standardized technique for research in reproductive biology and for advancing our understanding of paternal contributions to transgenerational inheritance
Therapeutic effects of vitamin D and omega-3 supplementation on HFHS diet-induced endothelial dysfunction in Wistar rats
No full textInternational audienceObesity impairs cardiovascular health through endothelial dysfunction, which is exacerbated by high-fat high-sugar (HFHS) diets through mechanisms involving chronic inflammation, oxidative stress, and insulin resistance. Nutritional interventions, specifically vitamin D (VD) and omega-3 fatty acids (ω3), have emerged as potential therapies to improve endothelial function and mitigate cardiovascular risks associated with obesity
Persistent organic pollutants in food systems: A comparative study across four contrasting socio-ecosystems: Portugal, Senegal, French Guiana, and Guadeloupe
No full textInternational audienceThis study quantifies persistent organic pollutants (POPs) in food across four territories undergoing dietary transitions: French Guiana, Guadeloupe, Senegal, and Portugal. A total of 200 local and imported food samplesfrom 12 categories were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). Concentrations varied by food matrix, region, and origin. The highest PCDDlevels were found in butter from Senegal (16.64 pg/g), and the highest PCDFs in leafy vegetables from Portugal (2.4 pg/g). Fish category showed the highest levels of dioxin-like PCBs (600.7 pg/g) and non-dioxin-like PCBs (3.6 ng/g). All values complied with EU Regulation 2023/915. To estimate dietary exposure, the maximum allowable daily intake (g of food/day) was calculated using Toxic Equivalents (TEQ), EFSA’s tolerable weekly intake (TWI: 2 pg TEQ/kg bw/week), and compared to national food consumption data. In Portugal, exposure from fish exceeded the TWI, highlighting the influence of regional contamination sources and dietary habits
Conception et mise en place de planches pédagogiques pour l'apprentissage de la pharmacologie et l'usage des médicaments en thérapeutique vétérinaire
No full textLa pharmacologie vétérinaire est perçue comme complexe par les étudiants, en raison de la quantité d’informations à mémoriser (molécules, récepteurs, effets). Pour faciliter son apprentissage, cette thèse propose la création de planches visuelles synthétiques, illustrant les mécanismes d’action des médicaments et leurs effets cliniques. Deux enquêtes menées auprès des étudiants VET2 et VET3 d’Oniris confirment ce besoin : plus de 85 % jugent la discipline difficile et souhaitent des supports visuels. En réponse, des schémas moléculaires (récepteurs, voies intracellulaires) et des pictogrammes cliniques (tachycardie, sédation, etc.) ont été conçus selon un code couleur cohérent. 24 planches thématiques ont été réalisées, intégrant ces visuels pour représenter les grandes classes de médicaments, en lien avec les objectifs pédagogiques des UE 51 et 66. L’approche vise à améliorer la compréhension, la mémorisation et l’application clinique de la pharmacologie. Ce travail illustre l’intérêt d’outils pédagogiques visuels, conçus avec rigueur scientifique et adaptés aux attentes des étudiants
Development of good practice guidelines for on-farm production of antibiotic-coated feed in aquaculture
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Bringing to light vinyl chloride oligomers, a class of polychlorinated alkanes differing from chlorinated paraffins
No full textInternational audiencePolyvinyl chloride (PVC) is one of the most widely used polymers, which contrasts with the low amount of literature on the leaching of associated additives and in particular unintended oligomers, a class of non-intentionally added substances (NIAS). This study sheds light on the occurrence of vinyl chloride oligomers (VCOs) in a variety of PVC analytical standards (n = 4), PVC items employed for construction, medical or food contact applications (n = 14), as well as in foodstuffs and environmental matrices (n = 10). Samples were analysed by liquid chromatography coupled to high-resolution mass spectrometry hyphenated with chloride-enhanced electrospray ionisation. Series of saturated (0VCO), monounsaturated (1VCO), diunsaturated (2VCO) and triunsaturated (3VCO) VCOs were revealed. The dominant series remained 1VCOs of the general formula C2nH3nCln, accounting for ∼80 % of VCOs in PVC standards. A risk of signal overlap was found between 0VCOs of the general formula C2nH3n+1Cln+1 (accounting for ∼8 % in PVC standards) and polychlorinated alkanes making up chlorinated paraffins, given that they share the same chemical formulas. A methodology for discriminating between signals arising from VCOs and chlorinated paraffins has been proposed. VCOs were detected in 88 % of the samples analysed (other than standards), and in particular in some foodstuffs and environmental matrices, suggesting that VCOs have the capacity to leach out of PVC materials, and thus contaminate food and the environment.Overall, these results call for greater attention to be paid to vinyl chloride oligomers and raise the question of whether they pose a risk to living organisms
The role of the immune system in osteoarthritis: mechanisms, challenges and future directions
No full textInternational audienceOsteoarthritis (OA) is a chronic joint disease that has long been considered a simple wear-and-tear condition. Over the past decade, research has revealed that various inflammatory features of OA, such as low-grade peripheral inflammation and synovitis, contribute substantially to the pathophysiology of the disease. Technological advances in the past 5 years have revealed a large diversity of innate and adaptive immune cells in the joints, particularly in the synovium and infrapatellar fat pad. Notably, the presence of synovial lymphoid structures, circulating autoantibodies and alterations in memory T cell and B cell populations have been documented in OA. These data indicate a potential contribution of self-reactivity to the disease pathogenesis, blurring the often narrow and inaccurate line between chronic inflammatory and autoimmune diseases. The diverse immune changes associated with OA pathogenesis can vary across disease phenotypes, and a better characterization of their underlying molecular endotypes will be key to stratifying patients, designing novel therapeutic approaches and ultimately ameliorating treatment allocation. Furthermore, examining both articular and systemic alterations, including changes in the gut–joint axis and microbial dysbiosis, could open up novel avenues for OA management
Lésions à l’encolure chez les truies et injections intramusculaires : une étude descriptive
No full textInternational audienceEn France, 5,6 % des truies réformées présentent des lésions à l’encolure nécessitant un parage des échines à l’abattoir (Uniporc Ouest 2023). Ces lésions apparaissent à la suite d’injections dans l’encolure des truies (vaccins et autres médicaments) par voie intramusculaire avec des injecteurs avec et sans aiguille. Il peut s’agir d’abcès ou de tissus de cicatrisation tels que les granulomes. Ces lésions sont considérées comme un problème important en élevage en raison de leurs conséquences : douleur, risque de septicémie et de mortalité, saisies à l’abattoir et risque d’immunisation altérée lorsqu’un vaccin est injecté dans des tissus lésés