Search results for "HUMAN HEALTH"
showing 10 items of 1622 documents
Olfactory neurons plasticity : environment effects during development
2012
In order to investigate the consequences of postnatal odorant exposure on a specific population of olfactory sensory neurons (OSNs), we have taken the following experimental approach. MOR23-GFP mice were daily exposed to Lyral for 21 days starting at birth and three lines of investigations were carried out. Using anatomical analysis we observe that the density of OSNs expressing MOR23 decreases after odorant exposure. This decrease concerns primarily matures OSN (MOR23-OMP+). In order to study molecular changes within individual OSNs, mRNA levels for olfactory signaling pathway components were quantitatively analyzed using qPCR on GFP-labeled neurons (7 per mouse). mRNAs for CNGA2, PDE1C an…
Aspects fonctionnels et pronostiques des cellules myéloïdes suppressives et de Foxp3 dans le cancer
2011
Evasion of immune surveillance by certain tumour cells seems to be a basic requirement for tumour development in preclinical models and in humans. The mechanisms by which the tumour mediates its immune evasion are manifold, and involve the majority of immune system cells. Among these, immunoregulatory cells such as myeloid-derived suppressor cells (MDSCs) or regulatory T lymphocytes (T-regs, which express the transcription factor Foxp3) appear to play a predominant role. The results presented in this work aim to improve our understanding of the functional and prognostic roles of myeloid suppressor cells and T-regs in cancer, focussing particularly on how these cells are modulated by chemoth…
Effets des polyphénols de vin rouge sur la prolifération cellulaire et sur le métabolisme du resvératrol
2011
It is known that moderate consumption of red wine may protect against many diseases, in particular because of its polyphenols. We studied in particular the effect of these polyphenols on colorectal cancer, one of the most common cancers in industrialized countries. Some purified polyphenols from red wine, like resveratrol and quercetin, showed antiproliferative effects against colorectal cancer cells.Our first approach was to use polyphenolic extracts from Burgundy red wine. We then studied their in vitro effects on human colorectal tumor cell lines SW480’s proliferation and the interactions between the polyphenols and the transport and metabolism of resveratrol; and secondly, the effects o…
Rôle des antigènes tissulaires de groupes sanguins humains A, B, H et Lewis dans l'évolution des Norovirus GII.4
2011
Noroviruses are one of the leading causes of gastroenteritis worldwide. Since 2002 successive GII.4 variants have circulated in the population before being replaced every 2-3 years, which raises questions about the role of their histo-blood group antigen (HBGAs) receptors in their evolution. We analyzed the interaction between representative GII.4 variants and HBGAs and determined the role of selected amino acids (aa) in the binding profiles. By mutagenesis, we showed that there was a strict structural requirement for the aa directly implicated in HBGA bindings. The ablation of the threonine 395 residue, an epidemiological feature of the post 2002 variants, allowed to gain the capacity to b…
Plasmalogen metabolism in retinal glial cells : interaction between cells during normal or pathological vascular development
2017
Retinal vascular disorders such as retinopathy of prematurity (ROP), diabetic retinopathy or age-related macular degeneration represent the first cause of vision loss at all ages in industrialized countries. Many epidemiological or animal studies have shown the involvement of polyunsaturated fatty acids (PUFA) in the regulation of vascular development and more specifically the beneficial properties of omega 3 PUFA (n-3 PUFA) against pathological vascularization. Those PUFA are esterified on glycerophospholipids (GP). GP are the primary constituents of the lipid bilayer of cell membranes. PUFA can be also esterified on a specific class of GP, called plasmalogens. Plasmalogens are characteriz…
Etude de NLRP3 dans les cellules myéloïdes immunosuppressives et les lymphocytes TCD4 dans un contexte de cancer
2013
The inflammasome NLRP3 (NOD like receptor pyd containing 3) is a multiprotein complex notably responsible for IL-1β (interleukine-1β) production, an inflammatory cytokine. Negative effects have been observed in various diseases including cancer. My thesis focuses on the effects of NLRP3 in cancer.In my first project, I studied the NLRP3 inflammasome activation in MDSC (myeloïd derived suppressor cells) after a chemotherapy treatment. Two chemotherapies, 5-Fluorouracil and Gemcitabine, are selectively able to kill MDSC, an immunosuppressive population growing during cancer evolution. MDSC’s death restores anti-tumor immunity for a while but another immunosuppressive population is established…
Effets du resvératrol et de formulations de micro-nutriments alimentaires sur les fonctions du muscle squelittique chez la souris et sur les cellules…
2012
A concept that has emerged in recent years is the use of micronutrients as therapeutic agents known for their anti-inflammatory, antioxidant, cardio-protective or anticarcinogenic proprieties. In this work, we studied the in vivo and in vitro mechanism of action of resveratrol and two natural formulations, one involved in the antioxidant effects (product "X") and the other (product "Y") involved in the correction of lipid disorders in people affected by metabolic syndrome. We characterized the pro-differentiating effect of a natural polyphenol, resveratrol, on C2C12 skeletal muscle cell line. This study showed that this polyphenol can induce the expression of muscle differentiation factors …
Implication de la plasticité cérébrale hypothalamique dans la régulation de l'homéostasie énergétique chez la souris : effet d'un régime gras
2012
The hypothalamus plays a crucial role in the control of energy balance. In adult brain, this area remain plastic and the cellular network can be rapidly modified under environmental pressures. Studies show than hypothalamic remodeling are disturbed when metabolic diseases such as obesity or type II diabetes are declared. In this study we hypothesized that a high fat diet (HFD) inducing obesity could rapidly causes cell modifications in the adult hypothalamus network. To answer this question, we have established a one week HFD mouse model, and evaluated to type of hypothalamic plasticity which are synaptic plasticity and neurogenesis. Our results show that HFD leads to an increase of the exc…
Hedonic sensations implicated in the control of human food intake : alimentary alliesthesia and sensory-specific satiety
2011
The control of food intake is a complex and multifactorial process controlled by the CNS. It is implicated in the regulation of body weight and the supply of energy substrates, as well as the supply of a panoply of nutrients to cover the specific needs of the organism. Among all the factors involved, hedonic sensations play an important role in guiding food selection and limitation of intake. The theoretical section of this thesis takes into account the physio-anatomical aspects of the control of food intake, in particular sensory pleasure and its evaluation, within the framework of the three principal hedonic phenomena: Conditioned Satiety (CS), Alimentary alliesthesia (AA) and sensory-spe…
Impact du système endocannabinoïdien sur la physiologie de l'obésité : effets de l'antagonisme des récepteurs CB1 sur le métabolisme glucido-lipidiqu…
2010
The endocannabinoïd system (ECS) is involved in many biological functions such as regulation of energy metabolism. Recently, several studies have shown an association between obesity and ECS overactivity. In addition, specific CB1R antagonists such as Rimonabant (SR141716) improved metabolic parameters in obese patients essentially through inactivation of central CB1R. However, peripheral CB1R inactivation could also contribute to the improvement of these parameters and it is this notion that we have studied. To this purpose, we tested the effects of SR141716 on obese mice in order to establish relationships between the ECS activity and lipid metabolism by looking more specifically to its r…