A Quantitative Assessment of Costimulation and Phosphatase Activity on Microclusters in Early T Cell Signaling

T cell signaling is triggered through stimulation of the T cell receptor and costimulatory receptors. Receptor activation leads to the formation of membrane-proximal protein microclusters. These clusters undergo tyrosine phosphorylation and organize multiprotein complexes thereby acting as molecular signaling platforms. Little is known about how the quantity and phosphorylation levels of microclusters are affected by costimulatory signals and the activity of specific signaling proteins. We combined micrometer-sized, microcontact printed, striped patterns of different stimuli and simultaneous analysis of different cell strains with image processing protocols to address this problem. First, we validated the stimulation protocol by showing that high expression levels CD28 result in increased cell spreading. Subsequently, we addressed the role of costimulation and a specific phosphotyrosine phosphatase in cluster formation by including a SHP2 knock-down strain in our system. Distinguishing cell strains using carboxyfluorescein succinimidyl ester enabled a comparison within single samples. SHP2 exerted its effect by lowering phosphorylation levels of individual clusters while CD28 costimulation mainly increased the number of signaling clusters and cell spreading. These effects were observed for general tyrosine phosphorylation of clusters and for phosphorylated PLCγ1. Our analysis enables a clear distinction between factors determining the number of microclusters and those that act on these signaling platforms.     

Delineating landscape-scale processes of hydrology and plant dispersal for species-rich fen conservation: the Operational Landscape Unit approach

Restoration and conservation of species-rich nature reserves requires inclusion of landscape-scale connections and transport processes such as hydrologic flows and species dispersal. These are important because they provide suitable habitat conditions and an adequate species pool. This study aimed at identifying the key hydrologic flows and plant dispersal processes affecting a landscape with species-rich fen reserves where restoration measures are carried out to set back succession. It also intended to use this information for delineating the area relevant for conservation planning on an Operational Landscape Unit map. The study was carried out for complexes of fen ponds in former turbaries in the Vechtplassen area, The Netherlands. A number of recent insights on plant dispersal were integrated with knowledge on hydrologic flows in the present approach. The results showed that groundwater discharge to ensure mesotrophic, base-rich conditions, should be enhanced by restoring the groundwater recharge areas NE of the reserves. A nearby lake with suitable water chemistry was also identified as a key source of surface water to feed the fens in dry periods. Water dispersal was identified as important within the fen reserves, whereas dispersal by daily migrating dabbling ducks, typically occurring over 2–3 km, was the most important route connecting the reserves with the surrounding landscape. The delineation of the Operational Landscape Unit for this region provides a basis for conservation and restoration that take fundamental landscape connections and transport processes into account. This unique approach simultaneously considers hydrological transport processes as well as species dispersal in the larger landscape beyond the reserves themselves and therefore leads to greater success of restoration and conservation.     

Different effects of monoamine oxidase inhibition on MPTP depletion of heart and brain catecholamines in mice

Pargyline, an inhibitor of monoamine oxidase type B (MAO-B), did not prevent the depletion of heart norepinephrine 24 hr after a single dose of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in mice. In mice killed 24 hr after the last of 4 daily doses of MPTP, the depletion of dopamine in the striatum and of norepinephrine in the frontal cortex was completely prevented by pargyline, but the depletion of heart norepinephrine was not prevented. These results with pargyline are the same as results obtained earlier with deprenyl, another selective inhibitor of MAO-B. The doses of pargyline and of deprenyl that were used resulted in almost complete inhibition of MAO-B activity (phenylethylamine as substrate) in brain, heart and liver of mice. Deprenyl did not inhibit MAO-A activity (serotonin as substrate) in brain, but pargyline caused some inhibition of MAO-A in brain. In heart and liver, serotonin was oxidized only at about 1/10 the rate of phenylethylamine oxidation, suggesting that MAO-B predominates in these tissues. Both pargyline and deprenyl caused some inhibition of serotonin deamination in heart and liver, suggesting that the oxidation may have been due partly to MAO-B. Experiments with selective MAO inhibitors in vitro showed that only about 20% of the oxidation of serotonin was occurring via MAO-B in heart and liver. The in vitro oxidation of MPTP by MAO in mouse brain, heart and liver was almost completely inhibited by pretreatment with either pargyline or deprenyl. Neither pargyline nor deprenyl had any significant effect on the concentrations of MPTP in brain or heart one-half hr after injection of MPTP into mice. The concentrations of the metabolite, MPP+ (1-methyl-4-phenyl-pyridinium), were markedly reduced in brain and in heart by pretreatment with either pargyline or deprenyl. The data suggest that MPP+ formation, which is necessary for the depletion of brain catecholamines after MPTP injection, may not be necessary for depletion of norepinephrine in heart. Since the oxidation of MPTP in vitro was inhibited more by pargyline or deprenyl pretreatment than was the appearance of MPP+ in vivo, the possibility exists that some MPP+ formation might occur by an enzyme other than MAO.     

De taalbarrière bij oudere Turkse vrouwen nader onderzocht

A growing group of migrants age in an environment in which the dominant language (L2) differs from their mother tongue (L1). This study considers the occurrence of a language barrier in accessing (information on) health and healthcare provisions, and under which circumstances a limited proficiency in the L2 negatively influences well-being for a group of older Turkish women in the Netherlands. Data from interviews with 39 Turkish females reveal that a limited L2 proficiency does not automatically result in a lower level of well-being. When individuals are well-embedded in a social network (and feel belonging to it), a limited L2 proficiency can be alleviated by either L1 assistance from their environment or by facilitating an interpreter in L2 situations. However, when such a network is absent, L2 situations can cause anxiety, which may have repercussions for well-being. Even though there is no clear one-on-one relationship between language and well-being, language does play a role in many (social) processes that influence well-being.     

Systematic Phenomics Analysis Deconvolutes Genes Mutated in Intellectual Disability into Biologically Coherent Modules

Intellectual disability (ID) disorders are genetically and phenotypically extremely heterogeneous. Can this complexity be depicted in a comprehensive way as a means of facilitating the understanding of ID disorders and their underlying biology? We provide a curated database of 746 currently known genes, mutations in which cause ID (ID-associated genes [ID-AGs]), classified according to ID manifestation and associated clinical features. Using this integrated resource, we show that ID-AGs are substantially enriched with co-expression, protein-protein interactions, and specific biological functions. Systematic identification of highly enriched functional themes and phenotypes revealed typical phenotype combinations characterizing process-defined groups of ID disorders, such as chromatin-related disorders and deficiencies in DNA repair. Strikingly, phenotype classification efficiently breaks down ID-AGs into subsets with significantly elevated biological coherence and predictive power. Custom-made functional Drosophila datasets revealed further characteristic phenotypes among ID-AGs and specific clinical classes. Our study and resource provide systematic insights into the molecular and clinical landscape of ID disorders, represent a significant step toward overcoming current limitations in ID research, and prove the utility of systematic human and cross-species phenomics analyses in highly heterogeneous genetic disorders.     

Going against the flow: a case for upstream dispersal and detection of uncommon dispersal events

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A mass stranding of seven Longman's beaked whales (Indopacetus pacificus) in New Caledonia,South Pacific

Seven Longman's beaked whales (Indopacetus pacificus) stranded together in southern New Caledonia on 16 November 2013 (one adult male, two adult females, two subadult females, one calf, and one unknown). At this time, we have no evidence to suggest that this event was an “atypical” mass stranding associated with active naval sonar or other anthropogenic activities. The adult females were slightly larger (618–640 cm) than the adult male (590 cm). The length of the calf (ca. 300 cm) suggests it was less than a year old. Five of the whales were sampled for mitochondrial (mt) DNA analysis to confirm species identification. All shared the same haplotype over 680 bp of the mtDNA control region. High concentrations of Hg, Fe, Se, Zn (all in the liver), and Cd (in the kidneys) were detected. Necropsies revealed plastic debris in the stomach of two of the whales. One of these same whales had chronic gastritis while the other had acute pleurisy and also tested positive for morbillivirus. This infection may have been a major factor behind this mass stranding event.