Search results for "PLASMA MEMBRANE"
showing 10 items of 92 documents
Endotoxaemia resulting from decreased serotonin tranporter (5-HTT) function: A reciprocal risk factor for depression and insulin resistance?
2015
International audience; Depression and diabetes are serious diseases with an increasing global prevalence. Intriguingly, recent meta-analyses have highlighted an asymmetrical relationship between the two conditions as depressed patients were found to display a higher risk of developing type 2 diabetes than those individuals suffering from diabetes are to become depressed. Based on recent findings, we favor a hypothesis where by decreased peripheral serotonin (5-HT) transporter (5-HTT) function is a reciprocal risk factor for the comorbidity of depression and diabetes, as it can trigger inflammatory pathogenetic mechanisms of both conditions. Higher intestinal levels of 5-HT and 5-HT3 recept…
Effect of family structure and TPH2 G-703T on the stability of dysregulation profile throughout adolescence
2015
Abstract Background Two different polymorphisms (TPH2 G-703T and 5-HTTLPR) involved in the serotonergic pathway have been reported to play a role, both alone and in interaction with the environment, in early and adult emotion regulation. As most of these studies are cross-sectional, we know little about the impact of these polymorphisms over time, particularly during adolescence. Methods Because we were interested in the effects of these polymorphisms and environment (i.e., family structure) at different time-points on the emotional dysregulation profile, we performed a path analysis model in a general adolescent population sample of a five-year follow-up study. Results We found a high stab…
Effects of two-carbon bridge region methoxylation of benztropine: discovery of novel chiral ligands for the dopamine transporter
2001
6-Methoxylated and 8-oxygenated benztropines were prepared and evaluated for their DAT and SERT activity (binding and uptake inhibition). Methoxylation at the two-carbon bridge of benztropine produced a novel class of potent and selective DAT ligands. An interesting enantioselectivity was also observed for this new class of chiral benztropines. The inactivity of the 8-oxygenated analogues seems to point out that, unlike cocaine and its analogues, interactions of benztropine ligands with DAT may be strongly governed by the nitrogen atom.
Synthesis and pharmacology of 6-substituted benztropines: discovery of novel dopamine uptake inhibitors possessing low binding affinity to the dopami…
2005
A series of 6alpha- and 6beta-substituted benztropines were synthesized. A marked enantioselectivity was observed for the 6beta-methoxylated benztropines, the (1R)-isomers being more potent than the corresponding (1S) compounds. The racemic 6alpha-methoxy-3-(4',4' '-difluorodiphenylmethoxy)tropane (5 g) was the most potent compound. It has been found that modifications at the 6-position of benztropine might reduce the DAT binding affinity, maintaining otherwise a significant dopamine uptake inhibitory activity. A reinvestigation of the absolute configuration of 6beta-methoxytropinone proved the 6R configuration for the (+)-enantiomer.
Synthesis and monoamine uptake inhibition of conformationally constrained 2β-carbomethoxy-3β-phenyl tropanes
2009
A series of 2beta-carbomethoxy-3beta-phenyl tropanes with conformationally constrained nitrogen substituents were synthesized as potential selective dopamine transporter ligands. These novel compounds were examined for their monoamine uptake inhibition potency at the human dopamine transporter (hDAT), the human serotonin transporter (hSERT) and the human noradrenalin transporter (hNET), stably expressed in human embryonic kidney cells (HEK). A SAR-study was conducted to determine the contribution of extended, 4-fluorinated, conformationally constrained C4 chains at the tropane nitrogen to human monoamine transporter affinity and selectivity.
ADHD and DAT1: Further evidence of paternal over-transmission of risk alleles and haplotype
2010
Contains fulltext : 87259.pdf (Publisher’s version ) (Closed access) We [Hawi et al. (2005); Am J Hum Genet 77:958-965] reported paternal over-transmission of risk alleles in some ADHD-associated genes. This was particularly clear in the case of the DAT1 3'-UTR VNTR. In the current investigation, we analyzed three new sample comprising of 1,248 ADHD nuclear families to examine the allelic over-transmission of DAT1 in ADHD. The IMAGE sample, the largest of the three-replication samples, provides strong support for a parent of origin effect for allele 6 and the 10 repeat allele (intron 8 and 3'-UTR VNTR, respectively) of DAT1. In addition, a similar pattern of over-transmission of paternal ri…
Involvement of the plasma membrane in saccharomyces cerevisiae resistance to hydric perturbations : key role of ergosterol
2011
Preservation of microorganisms of interest (ferments, probiotics) in dry form is widespread in the industry. However, the dehydration processes lead to variable survival rates according to the group, species and strain of microorganism considered, but also according to the type of process used (drying, freeze drying, freezing). The plasma membrane (PM), by its position between the intra-and extracellular environment, is a target of hydric perturbations. Changes in this structure during hydric stresses are described to be directly involved in microorganism death. Understanding of membrane responses occurring during a dehydration/rehydration cycle is essential to maximize the survival of micr…
Rôle de la membrane plasmique dans la survie des microorganismes à la déshydratation : Contribution à l’optimisation de procédés de conservation des …
2010
Cette synthèse est consacrée au rôle de la membrane plasmique des microorganismes, à travers ses évolutions structurales et fonctionnelles, dans la survie à la déshydratation. Elle comprend une première partie dans laquelle sont regroupés les principaux résultats portant sur l’influence de la déshydratation sur la survie microbienne, sur le comportement membranaire in situ et sur les mécanismes physiques de la déstabilisation membranaire. La deuxième partie est consacrée à la transposition de cette compréhension aux applications de déshydratation industrielle des microorganismes. Elle porte sur le développement d’un procédé de déshydratation des microorganismes et sur la mise au point d’out…
Influence of phytosterols on the structural and dynamic properties of plant plasma membrane
2008
National audience; The complex mixture of sterols, namely phytosterols, found in the plasma membrane (PM) of plant cells is an intriguing characteristic. In the present work, we characterized the sterol composition of tobacco BY-2 cell PM, and we adapted a sterol manipulation method to this plant material. Methyl-b-cyclodextrin was found to induce a drastic reduction of the PM total free sterol content, with a low specificity for the different phytosterols, and without effect on steryl-conjugates. The consequences of phytosterols depletion were investigated by means of fluorescence spectroscopy and biochemical detergent resistant membrane (DRM) fraction purification methods. Data obtained w…
Plasma membrane microdomains in plants: for which physiological roles?
2007
International audience; A large body of evidence supports the existence, in membrane from animal and yeast cells, of functional microdomains playing important roles in protein sorting, signal transduction, or infection by pathogens (1). We demonstrated the presence, in plants, of detergent resistant fractions isolated from plasma membrane, with a lipidic composition similar to animal microdomains (2). Electrophoresis experiments indicated that these fractions were able to recruit a specific set of plasma membrane proteins and exclude others. We used mass spectrometry to give an extensive description of a tobacco plasma membrane microdomains. This led to the identification of 145 proteins wh…