Search results for "regulator"
showing 10 items of 1009 documents
The role of regulatory T cell (Treg) subsets in gestational diabetes mellitus.
2014
Physiological changes during normal pregnancy are characterized by an inflammatory immune response and insulin resistance. Therefore, we hypothesize that gestational diabetes mellitus (GDM) may be caused by an inappropriate adaption of the maternal immune system to pregnancy. In this study we examined the role of regulatory T cell (Treg) differentiation for the development of GDM during pregnancy. We used six-colour flow cytometric analysis to demonstrate that the total CD4(+) CD127(low+/-) CD25(+) forkhead box protein 3 (FoxP3(+)) T(reg) pool consists of four different T(reg) subsets: naive CD45RA(+) T(regs), HLA-DR(-) CD45RA(-) memory T(regs) (DR(-) T(regs)) and the highly differentiated …
C4-dicarboxylate carriers and sensors in bacteria
2002
AbstractBacteria contain secondary carriers for the uptake, exchange or efflux of C4-dicarboxylates. In aerobic bacteria, dicarboxylate transport (Dct)A carriers catalyze uptake of C4-dicarboxylates in a H+- or Na+-C4-dicarboxylate symport. Carriers of the dicarboxylate uptake (Dcu)AB family are used for electroneutral fumarate:succinate antiport which is required in anaerobic fumarate respiration. The DcuC carriers apparently function in succinate efflux during fermentation. The tripartite ATP-independent periplasmic (TRAP) transporter carriers are secondary uptake carriers requiring a periplasmic solute binding protein. For heterologous exchange of C4-dicarboxylates with other carboxylic …
Calorie Restriction in Mammals and Simple Model Organisms
2014
Calorie restriction (CR), which usually refers to a 20–40% reduction in calorie intake, can effectively prolong lifespan preventing most age-associated diseases in several species. However, recent data from both human and nonhumans point to the ratio of macronutrients rather than the caloric intake as a major regulator of both lifespan and health-span. In addition, specific components of the diet have recently been identified as regulators of some age-associated intracellular signaling pathways in simple model systems. The comprehension of the mechanisms underpinning these findings is crucial since it may increase the beneficial effects of calorie restriction making it accessible to a broad…
Hormonal regulation of S-adenosylmethionine synthase transcripts in pea ovaries
1996
Two cDNA clones coding for S-adenosyl-L-methionine synthase (SAMs, EC 2.5.1.6) have been isolated from a cDNA library of gibberellic acid-treated unpollinated pea ovaries. Both cDNAs were sequenced showing a high degree of identity but coding for different SAMs polypeptides. The presence of two SAMs genes in pea was further confirmed by Southern analysis. Expression of the SAMs genes in the pea plant was found at different levels in vegetative and reproductive tissues. We characterized the expression levels of SAMs genes during the development or senescence of pea ovaries. Northern analysis showed that transcription of SAMs genes in parthenocarpic fruits was upregulated by auxins in the sam…
Wine yeast sirtuins and Gcn5p control aging and metabolism in a natural growth medium.
2012
Grape juice fermentation by wine yeast is an interesting model to understand aging under conditions closer to those in nature. Grape juice is rich in sugars and, unlike laboratory conditions, the limiting factor for yeast growth is nitrogen. We tested the effect of deleting sirtuins and several acetyltransferases to find that the role of many of these proteins during grape juice fermentation is the opposite to that under standard laboratory aging conditions using synthetic complete media. For instance, . SIR2 deletion extends maximum chronological lifespan in wine yeasts grown under laboratory conditions, but shortens it in winemaking. Deletions of sirtuin . HST2 and acetyltransferase . GCN…
Negative Regulation of β Enolase Gene Transcription in Embryonic Muscle Is Dependent upon a Zinc Finger Factor That Binds to the G-rich Box within th…
1998
We have previously identified a muscle-specific enhancer within the first intron of the human beta enolase gene. Present in this enhancer are an A/T-rich box that binds MEF-2 protein(s) and a G-rich box (AGTGGGGGAGGGGGCTGCG) that interacts with ubiquitously expressed factors. Both elements are required for tissue-specific expression of the gene in skeletal muscle cells. Here, we report the identification and characterization of a Kruppel-like zinc finger protein, termed beta enolase repressor factor 1, that binds in a sequence-specific manner to the G-rich box and functions as a repressor of the beta enolase gene transcription in transient transfection assays. Using fusion polypeptides of b…
Agonist potency differentiates G protein activation and Ca2+ signalling by the orexin receptor type 1.
2005
The G protein coupling characteristics of a flag epitope-tagged orexin receptor type 1 (OX1R) was investigated in HEK293 cells. Immunoprecipitation of the OX1R and immunoblotting revealed interactions with Gq/G11 proteins as well as with Gs and Gi proteins. Stimulation with orexin-A did not affect the ability of the OX1R to coprecipitate Gq/G11 proteins, but it robustly elevated the intracellular concentration of Ca2+, [Ca2+]i. No changes in cAMP levels could be detected upon receptor stimulation. To get further insight into the functional correlation of G protein activation and Ca2+ signalling, we used baculovirus transduction to express chimeric G proteins, containing the Galphas protein …
Imidazole derivative KK-42 reduces ecdysteroid titers and interferes with reproductive processes in adult females of Tenebrio molitor
2004
0048-3575 doi: DOI: 10.1016/j.pestbp.2004.07.004; KK-42, an imidazole derivative considered as potent inhibitor of ecdysteroid biosynthesis, was tested on adult females of Tenebrio molitor. The compound was applied topically (0.1, 1, 5, and 10 μg/insect) on 0- or 2-day-old adult females or added to the culture medium (1 and 10 μM) of ovaries. To test the effect of KK-42 on the reproduction capacity, ovaries were explanted from 2- and 4-day-old females corresponding, respectively, to follicles at the beginning and the end of vitellogenesis. KK-42 treatment reduced the fecundity and the longevity of females, and in addition, it delayed oviposition and affected growth and development of oocyte…
Cutting type and IBA treatment duration affect Teucrium fruticans adventitious root quality
2014
Root development of stem cuttings of Silver Germander (Teucrium fruticans) was investigated in relation to cutting type and indole-3-butyric acid (IBA) treatment. Terminal cuttings of a clone grown in Sicily were trimmed to three types: terminal cuttings with apex (TWA), terminal cuttings without apex (TWOA) or sub-terminal cuttings (ST). To verify the cutting response to exogenous auxin, cuttings were dipped to a 2.0 cm depth in a 0.5% indole-3-butyric acid solution for 0, 5 or 7 minutes. Overall percent survival was 97 to 98%. Rooting percent, root number and root length were affected by cutting type and indole-3-butyric acid treatment. In general, TWA cuttings demonstrated a higher capac…
Interruption of CD28-mediated costimulation during allergen challenge protects mice from allergic airway disease
2012
Background Allergic asthma is a T H 2-promoted hyperreactivity with an immediate, IgE, and mast cell–dependent response followed by eosinophil-dominated inflammation and airway obstruction. Objective Because costimulation by CD28 is essential for T H 2 but not T H 1 responses, we investigated the effect of selective interference with this pathway in mice using the models of ovalbumin and house dust mite–induced airway inflammation. Methods To study the role of CD28 in the effector phase of allergic airway inflammation, we developed an inducibly CD28-deleting mouse strain or alternatively used a CD28 ligand-binding site–specific mouse anti-mouse mAb blocking CD28 engagement. Results We show …