Search results for "acides gras"

Monounsaturated fatly acid metabolism and colon cancer cells proliferation : role of Stearoyl-CoA desaturase-1 and effect of conjugated linoleic acid…

2012

Cancer cells adapt their metabolism in response to signals from the microenvironment and proliferation. Thus, MonoUnsaturated Fatty Acid (MUFA) synthesis is increased in colon cancer cells, and associated with increased Stearoyl-CoA Desaturase (SCD) activity, the rate limiting enzyme of MUFA biosynthesis. Polyunsaturated Fatty Acid (PUFA), as isomers of conjugated linoleic acid (CLA), exert inhibitor activity on SCD-1 and have anti-cancer properties, but their mechanisms are not yet clear. In this context, the aim of this work was first to evaluate the role of SCD-1 in the proliferation of colon cancer cells (CCC) and to define the underlying mechanisms. In a second time, we provide new inf…

New insights into the pharmacology of the short-chain free fatty acid receptors 2 and 3

2011

Metabolic diseases, such as diabetes, dyslipidemia or obesity, are more and more weighing on public health expenses in developed countries. Despite active research, these widespread diseases remain difficult to handle. Promising new therapeutic strategies against metabolic diseases include the development of drugs targeting the free fatty acid receptors, as key players in metabolism homeostasis. In this context, the current PhD thesis focuses on the study of two G protein-coupled receptors, namely the short-chain free fatty acid receptors 2 (FFA2) and 3 (FFA3). First, we investigated the expression of the two receptors of interest in a variety of cell types. Then, in order to study the phar…

Cellular metabolic alteration : the voice of monoinsaturated fatty acid as therapeutic target

2010

Stearoyl Co-A desaturase (SCD) is the key enzyme of the metabolism of mono-unsaturated fatty acids (MUFA). Its activity  9 desaturase introduces a double bond cis in position 9 of saturated fatty acids (SFA), induced formation of MUFA. Impaired biosynthesis of MUFA is involved in many diseases such as cancer and cardiovascular disease. Cancer cells have a de novo synthesis of fatty acids increased with an accumulation MUFA. This change in the metabolism of fatty acids is associated with overexpression SCD1 which catalyzes the conversion of saturated fatty acids, monounsaturated fat. Several reports have shown that inhibition of SCD1 leads to blockage of proliferation and induction of apopt…

Réponses comportementales et préférences envers les acides gras à longue chaîne chez Drosophila melanogaster

2011

Fatty-acids (FAs) are crucial for animal survival and reproduction since these molecules are involved in many metabolic pathways and constitute a substantial store of energy. Despite the strong relationship established between excessive FA consumption and severe human etiologies (obesity, cancer, vascular diseases), our knowledge of the mechanisms underlying FA perception and preference is limited particularly in invertebrates. This is one of the reasons why we decided to investigate, during our PhD thesis, the perception of long-chain FAs (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3), using the model species Drosophila melanogaster. We have also attempted to characterize some of the biologica…

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…

Peroxydation in vivo et in vitro des acides gras polyinsaturés

2007

It is well admitted that polyunsaturated fatty acids are the most sensitive fatty acids to oxidative damage because of their high number of double bonds. This concept could not be confirmed by in vitro, animal, or human studies since unexpected or even contradictory results were obtained. The explanation of that is probably related to the methods evaluating lipid peroxidation whose relevance is not always established, but especially to movements of polyunsaturated fatty acids within lipoproteins that results in their protection. This short review aims to discuss the main results related to this topic.

Regulation of the activity of the Cholesteryl Ester Tranfer Protein (CETP) : electrostatics interactions with carboxylic derivatives (Non Esterified …

1997

In human plasma, the cholesteryl ester transfer protein (CETP) plays a key role in lipoprotein metabolism by promoting the net mass transfer of cholesteryl esters from HDL towards apoB-containing lipoproteins, and the transfer of triglycerides from VLDL towards HDL and LDL. Thus CETP arises as a potentially important factor in plasma lipoproteins metabolism, a statement which raised a considerable interest in identifying the factors which may regulate CETP activity.In our in vitro studies, we demonstrated that amphipathic molecules (non esterified fatty acids and retinoic acids) constituted of one carboxylic head group and one hydrophobic carbon chain are able to increase the cholesteryl es…

Alimentation et vision

2016

Micronutrition : de la théorie à l'application en clinique

2010

National audience; Les prévisions démographiques s'attendent à un accroissement important de la population âgée et très âgée dans les décennies à venir. La prévalence des pathologies oculaires occupe la deuxième place dans cette frange de la population, laissant entrevoir une réelle explosion du coût social et économique associé à la prise en charge des patients. Pourtant, des données théoriques suggèrent que certains nutriments, en particulier lipophiles, pourraient participer à prévenir les effets du vieillissement sur la rétine et le développement pathologique. Ces hypothèses sont corroborées par des données épidémiologiques qui renforcent l'association entre la consommation d'acides gra…