Homocysteine metabolism pathway is involved in the control of glucose homeostasis: a cystathionine beta synthase deficiency study in mouse

Cystathionine beta synthase (CBS) catalyzes the first step of the transsulfuration pathway from homocysteine to cystathionine, and its deficiency leads to hyperhomocysteinemia (HHcy) in humans and rodents. To date, scarce information is available about the HHcy effect on insulin secretion, and the link between CBS activity and the setting of type 2 diabetes is still unknown. We aimed to decipher the consequences of an inborn defect in CBS on glucose homeostasis in mice. We used a mouse model heterozygous for CBS (CBS+/-) that presented a mild HHcy. Other groups were supplemented with methionine in drinking water to increase the mild to intermediate HHcy, and were submitted to a high-fat diet (HFD). We measured the food intake, body weight gain, body composition, glucose homeostasis, plasma homocysteine level, and CBS activity. We evidenced a defect in the stimulated insulin secretion in CBS+/- mice with mild and intermediate HHcy, while mice with intermediate HHcy under HFD presented an improvement in insulin sensitivity that compensated for the decreased insulin secretion and permitted them to maintain a glucose tolerance similar to the CBS+/+ mice. Islets isolated from CBS+/- mice maintained their ability to respond to the elevated glucose levels, and we showed that a lower parasympathetic tone could, at least in part, be responsible for the insulin secretion defect. Our results emphasize the important role of Hcy metabolic enzymes in insulin secretion and overall glucose homeostasis

Front Behav Neurosci

Cognitive impairment in Down syndrome (DS) has been linked to increased synaptic inhibition. The underlying mechanisms remain unknown, but memory deficits are rescued in DS mouse models by drugs targeting GABA receptors. Similarly, administration of epigallocatechin gallate (EGCG)-containing extracts rescues cognitive phenotypes in Ts65Dn mice, potentially through GABA pathway. Some developmental and cognitive alterations have been traced to increased expression of the serine-threonine kinase DYRK1A on Hsa21. To better understand excitation/inhibition balance in DS, we investigated the consequences of long-term (1-month) treatment with EGCG-containing extracts in adult mBACtgDyrk1a mice that overexpress Dyrk1a. Administration of POL60 rescued components of GABAergic and glutamatergic pathways in cortex and hippocampus but not cerebellum. An intermediate dose (60 mg/kg) of decaffeinated green tea extract (MGTE) acted on components of both GABAergic and glutamatergic pathways and rescued behavioral deficits as demonstrated on the alternating paradigm, but did not rescue protein level of GABA-synthesizing GAD67. These results indicate that excessive synaptic inhibition in people with DS may be attributable, in large part, to increased DYRK1A dosage. Thus, controlling the level of active DYRK1A is a clear issue for DS therapy. This study also defines a panel of synaptic markers for further characterization of DS treatments in murine models

Les différences de salaires entre entreprises. Etude micro-économique

This paper in studying the formation of individual wages structure through some deflned jobs among sets of flrms belonging to the same sector or to the same labor-market. A decomposition of the variance of individual wages, for every job, into an internai wage-variance (inside the firm) and an « inter-firms » wage-variance shows that the differentials of average wages between flrms play an important role in the formation of the wage-structure. Such a resuit urget to go further in studying the « firm's effect » on the wage level. This was done in two directions : 1° by studying the «firm's effect» consistency according to the varions jobs and by observing eventual systematic selection policies of the manpower ; 2° by studying the laws of the « firm's effect » on the labor's price level : analysis of the relationships between labor's price and total productivity surplus by factor unit ; analysis of the relationships between « labor-market effect » and firm independence with respect to this market.Cet article étudie la formation de la structure des salaires individuels pour des emplois précis et dans des ensembles d'entreprises appartenant à un même secteur ou à un même marché du travail. Une décomposition de la variance des salaires individuels pour chaque métier, entre variance des salaires interne aux entreprises et variance des salaires entre entreprises, montre que les différences de salaires moyens entre entreprises jouent un rôle essentiel dans la formation de la structure des salaires. Ce résultat conduit à approfondir l'étude , de l'effet de l'entreprise sur le niveau des salaires. Cet approfondissement est mené dans deux directions : 1 ° par une étude de la cohérence de « l'effet entreprise » selon les métiers et par l'examen d'éventuelles pratiques de sélection systématique de main-d'œuvre ; 2° par une étude des lois de l'effet de l'entreprise sur le niveau du prix du travail : étude des relations entre prix du travail et surplus de productivité globale par unité de facteur ; étude des relations entre effet de marché du travail et autonomie des entreprises par rapport au marché.Silvestre J.-J., Daubigney J.-P., Fizaine F. Les différences de salaires entre entreprises. Etude micro-économique. In: Revue économique, volume 22, n°2, 1971. pp. 214-246

Les différences de salaires entre entreprises. Etude micro-économique

[fre] Cet article étudie la formation de la structure des salaires individuels pour des emplois précis et dans des ensembles d'entreprises appartenant à un même secteur ou à un même marché du travail.. Une décomposition de la variance des salaires individuels pour chaque métier, entre variance des salaires interne aux entreprises et variance des salaires entre entreprises, montre que les différences de salaires moyens entre entreprises jouent un rôle essentiel dans la formation de la structure des salaires. Ce résultat conduit à approfondir l'étude , de l'effet de l'entreprise sur le niveau des salaires. Cet approfondissement est mené dans deux directions :. 1 ° par une étude de la cohérence de « l'effet entreprise » selon les métiers et par l'examen d'éventuelles pratiques de sélection systématique de main-d'œuvre ;. 2° par une étude des lois de l'effet de l'entreprise sur le niveau du prix du travail : étude des relations entre prix du travail et surplus de productivité globale par unité de facteur ; étude des relations entre effet de marché du travail et autonomie des entreprises par rapport au marché. [eng] This paper in studying the formation of individual wages structure through some deflned jobs among sets of flrms belonging to the same sector or to the same labor-market.. A decomposition of the variance of individual wages, for every job, into an internai wage-variance (inside the firm) and an « inter-firms » wage-variance shows that the differentials of average wages between flrms play an important role in the formation of the wage-structure. Such a resuit urget to go further in studying the « firm's effect » on the wage level. This was done in two directions :. 1° by studying the «firm's effect» consistency according to the varions jobs and by observing eventual systematic selection policies of the manpower ;. 2° by studying the laws of the « firm's effect » on the labor's price level : analysis of the relationships between labor's price and total productivity surplus by factor unit ; analysis of the relationships between « labor-market effect » and firm independence with respect to this market.

Écologie de la restauration : Rencontre des spécialistes de la restauration écologique des écosystème

International audienc

Alterations in the Serotonin and Dopamine Pathways by Cystathionine Beta Synthase Overexpression in Murine Brain

International audienc

Basonuclin 2 has a function in the multiplication of embryonic craniofacial mesenchymal cells and is orthologous to disco proteins

Basonuclin 2 is a recently discovered zinc finger protein of unknown function. Its paralog, basonuclin 1, is associated with the ability of keratinocytes to multiply. The basonuclin zinc fingers are closely related to those of the Drosophila proteins disco and discorelated, but the relation between disco proteins and basonuclins has remained elusive because the function of the disco proteins in larval head development seems to have no relation to that of basonuclin 1 and because the amino acid sequence of disco, apart from the zinc fingers, also has no similarity to that of the basonuclins. We have generated mice lacking basonuclin 2. These mice die within 24 h of birth with a cleft palate and abnormalities of craniofacial bones and tongue. In the embryonic head, expression of the basonuclin 2 gene is restricted to mesenchymal cells in the palate, at the periphery of the tongue, and in the mesenchymal sheaths that surround the brain and the osteocartilagineous structures. In late embryos, the rate of multiplication of these mesenchymal cells is greatly diminished. Therefore, basonuclin 2 is essential for the multiplication of craniofacial mesenchymal cells during embryogenesis. Non-Drosophila insect databases available since 2008 reveal that the basonuclins and the disco proteins share much more extensive sequence and gene structure similarity than noted when only Drosophila sequences were examined. We conclude that basonuclin 2 is both structurally and functionally the vertebrate ortholog of the disco proteins. We also note the possibility that some human craniofacial abnormalities are due to a lack of basonuclin 2

Les âges du fer dans la vallée de la Saône (VIIe - Ier siècles avant notre ère)

La vallée de la Saône et ses environs se distinguent par leur richesse archéologique pour les deux Ages du fer et pour les vestiges relevant de la métallurgie ancienne. La comparaison des vestiges textiles, tombes à épées et tous les aspects de la paléométallurgie du bronze : mines, minerais, techniques de fabrication apporte des précisions sur cette période