203 research outputs found
Differences in the signaling pathways of α1A- and α1B-adrenoceptors are related to different endosomal targeting
Aims: To compare the constitutive and agonist-dependent endosomal trafficking of α1A- and α1B-adrenoceptors (ARs) and to establish if the internalization pattern determines the signaling pathways of each subtype.
Methods: Using CypHer5 technology and VSV-G epitope tagged α1A- and α1B-ARs stably and transiently expressed in HEK 293 cells, we analyzed by confocal microscopy the constitutive and agonist-induced internalization of each subtype, and the temporal relationship between agonist induced internalization and the increase in intracellular calcium (determined by FLUO-3 flouorescence), or the phosphorylation of ERK1/2 and p38 MAP kinases (determined by Western blot).
Results and Conclusions: Constitutive as well as agonist-induced trafficking of α1A and α1B ARs maintain two different endosomal pools of receptors: one located close to the plasma membrane and the other deeper into the cytosol. Each subtype exhibited specific characteristics of internalization and distribution between these pools that determines their signaling pathways: α1A-ARs, when located in the plasma membrane, signal through calcium and ERK1/2 pathways but, when translocated to deeper endosomes, through a mechanism sensitive to β-arrestin and concanavalin A, continue signaling through ERK1/2 and also activate the p38 pathway. α1B-ARs signal through calcium and ERK1/2 only when located in the membrane and the signals disappear after endocytosis and by disruption of the membrane lipid rafts by methyl-β-cyclodextrin
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Vascular endothelial growth factor and tryptase changes after chemoembolization in hepatocarcinoma patients
AIM: To evaluate vascular endothelial growth factor
(VEGF) and tryptase in hepatocellular cancer (HCC)
before and after trans-arterial chemoembolization
(TACE).
METHODS: VEGF and tryptase serum concentrations
were assessed from 71 unresectable HCC patients
before and after hepatic TACE performed by binding
DC-Beads® to doxorubicin. VEGF levels were examined
for each serum sample using the Quantikine Human
VEGF-enzyme-linked immuno-absorbent assay (ELISA),
whereas tryptase serum concentrations were assessed
for each serum sample by means of fluoro-enzyme
immunoassay (FEIA) using the Uni-CAP100 tool.
Differences between serum VEGF and tryptase values
before and after TACE were evaluated using Student t
test. Person's correlation was used to assess the degree
of association between the two variables.
RESULTS: VEGF levels and serum tryptase in HCC patients before TACE had a mean value and standard
deviation (SD) of 114.31 ± 79.58 pg/mL and 8.13
± 3.61 μg/L, respectively. The mean levels and SD
of VEGF levels and serum tryptase in HCC patients
after TACE were 238.14 ± 109.41 pg/mL and 4.02 ±
3.03 μg/L. The changes between the mean values of
concentration of VEGF and tryptase before treatment
and after treatment was statistically significant (P <
0.000231 and P < 0.00124, by Wilcoxon-Mann-Whitney
respectively). A significant correlation between VEGF
levels before and after TACE and between tryptase
levels before and after TACE was demonstrated (r =
0.68, P = 0.003; r = 0.84, P = 0.000 respectively).
CONCLUSION: Our pilot results suggest that the
higher serum VEGF levels and the lower tryptase levels
following TACE may be potential biomarkers changing
in response to therapy
Gamma frequency entrainment attenuates amyloid load and modifies microglia
Changes in gamma oscillations (20-50 Hz) have been observed in several neurological disorders. However, the relationship between gamma oscillations and cellular pathologies is unclear. Here we show reduced, behaviourally driven gamma oscillations before the onset of plaque formation or cognitive decline in a mouse model of Alzheimer's disease. Optogenetically driving fast-spiking parvalbumin-positive (FS-PV)-interneurons at gamma (40 Hz), but not other frequencies, reduces levels of amyloid-β (Aβ)[subscript 1-40] and Aβ [subscript 1-42] isoforms. Gene expression profiling revealed induction of genes associated with morphological transformation of microglia, and histological analysis confirmed increased microglia co-localization with Aβ. Subsequently, we designed a non-invasive 40 Hz light-flickering regime that reduced Aβ[subscript 1-40] and Aβ[subscript 1-42] levels in the visual cortex of pre-depositing mice and mitigated plaque load in aged, depositing mice. Our findings uncover a previously unappreciated function of gamma rhythms in recruiting both neuronal and glial responses to attenuate Alzheimer's-disease-associated pathology.National Institutes of Health (U.S.) (Grant 1R01EY023173)National Institutes of Health (U.S.) (Grant 1DP1NS087724)National Institutes of Health (U.S.) (Grant RF1AG047661)National Institutes of Health (U.S.) (Grant ROIGM104948
Spreading order: religion, cooperative niche construction, and risky coordination problems
Adaptationists explain the evolution of religion from the cooperative effects of religious commitments, but which cooperation problem does religion evolve to solve? I focus on a class of symmetrical coordination problems for which there are two pure Nash equilibriums: (1) ALL COOPERATE, which is efficient but relies on full cooperation; (2) ALL DEFECT, which is inefficient but pays regardless of what others choose. Formal and experimental studies reveal that for such risky coordination problems, only the defection equilibrium is evolutionarily stable. The following makes sense of otherwise puzzling properties of religious cognition and cultures as features of cooperative designs that evolve to stabilise such risky exchange. The model is interesting because it explains lingering puzzles in the data on religion, and better integrates evolutionary theories of religion with recent, well-motivated models of cooperative niche construction
Groucho binds two conserved regions of LEF-1 for HDAC-dependent repression
<p>Abstract</p> <p>Background</p> <p><it>Drosophila </it>Groucho and its human Transducin-like-Enhancer of Split orthologs (TLEs) function as transcription co-repressors within the context of Wnt signaling, a pathway with strong links to cancer. The current model for how Groucho/TLE's modify Wnt signaling is by direct competition with β-catenin for LEF/TCF binding. The molecular events involved in this competitive interaction are not defined and the actions of Groucho/TLEs within the context of Wnt-linked cancer are unknown.</p> <p>Methods</p> <p>We used <it>in vitro </it>protein interaction assays with the LEF/TCF family member LEF-1, and <it>in vivo </it>assays with Wnt reporter plasmids to define Groucho/TLE interaction and repressor function.</p> <p>Results</p> <p>Mapping studies reveal that Groucho/TLE binds two regions in LEF-1. The primary site of recognition is a 20 amino acid region in the Context Dependent Regulatory domain. An auxiliary site is in the High Mobility Group DNA binding domain. Mutation of an eight amino acid sequence within the primary region (RFSHHMIP) results in a loss of Groucho action in a transient reporter assay. <it>Drosophila </it>Groucho, human TLE-1, and a truncated human TLE isoform Amino-enhancer-of-split (AES), work equivalently to repress LEF-1•β-catenin transcription in transient reporter assays, and these actions are sensitive to the HDAC inhibitor Trichostatin A. A survey of Groucho/TLE action in a panel of six colon cancer cell lines with elevated β-catenin shows that Groucho is not able to repress transcription in a subset of these cell lines.</p> <p>Conclusion</p> <p>Our data shows that Groucho/TLE repression requires two sites of interaction in LEF-1 and that a central, conserved amino acid sequence within the primary region (F S/T/P/xx y I/L/V) is critical. Our data also reveals that AES opposes LEF-1 transcription activation and that both Groucho and AES repression require histone deacetylase activity suggesting multiple steps in Groucho competition with β-catenin. The variable ability of Groucho/TLE to oppose Wnt signaling in colon cancer cells suggests there may be defects in one or more of these steps.</p
Perceived quality of physiotherapist-led orthopaedic triage compared with standard practice in primary care: a randomised controlled trial
BACKGROUND: Physiotherapist-led orthopaedic triage, where physiotherapists diagnose and determine management plans, aims to enhance effectiveness and provide the best care. However, scientific evidence for the effectiveness of this model of care remains limited, and there are few studies reporting on patients’ perceptions of the care provided. The purpose of this study was to evaluate patients’ perceived quality of care in a physiotherapist-led orthopaedic triage in primary care, compared with standard practice. METHODS: In a randomised controlled trial, patients of working age referred for orthopaedic consultation at a primary healthcare clinic in Sweden received either physiotherapist-led triage (n = 102) or standard practice (orthopaedic surgeon assessment) (n = 101). Neither subjects nor clinicians were blinded. The questionnaire Quality from the Patient's Perspective (QPP) was used to evaluate perceived quality of care focusing on the caregivers’ medical-technical competence and identity-orientated approach. Also, to what extent patients’ expectations were met, and their intention to follow advice was evaluated. RESULTS: For this study, 163 patients (80 %) were analysed (physiotherapist-led triage (n = 83), standard practice (n = 80)). Participants perceived significantly higher quality of care with the triage than with the standard practice in regards to receiving best possible examination and treatment (medical-technical competence) (p < 0.001). This was also found in regards to receiving information about examination and treatment (p < 0.001), results (p < 0.001), and self-care (p < 0.001), the caregiver’s understanding (p < 0.001), respect (p < 0.001) and commitment (p < 0.001) as well as the opportunity to participate in decision-making (p = 0.01) (identity-orientated approach). Participants in the physiotherapist-led triage group reported to a significantly higher extent that their expectations of the treatment were met (p < 0.001), as well as the intent to follow the advice and instructions received (p = 0.019). CONCLUSIONS: This paper reports on patients’ perceptions of quality of care in a physiotherapist-led orthopaedic triage compared with standard practice. Patients in both groups reported that they perceived good quality of care, with the patients in the physiotherapist-led triage reporting significantly higher perceived quality of care than those in the standard practice group. This model of care seems to meet patients’ expectations and result in a greater intention to follow advice and instructions for self-management. Our findings are in line with existing literature that this model of care provides an opportunity to shape patient-centered care that can improve access and offer care on the most appropriate level, with maintained good quality of care. TRIAL REGISTRATION: Clinical Trials NCT02265172. Registered 10 June 201
Isolation and identification of actin-binding proteins in Plasmodium falciparum by affinity chromatography
γ-Tubulin 2 Nucleates Microtubules and Is Downregulated in Mouse Early Embryogenesis
γ-Tubulin is the key protein for microtubule nucleation. Duplication of the γ-tubulin gene occurred several times during evolution, and in mammals γ-tubulin genes encode proteins which share ∼97% sequence identity. Previous analysis of Tubg1 and Tubg2 knock-out mice has suggested that γ-tubulins are not functionally equivalent. Tubg1 knock-out mice died at the blastocyst stage, whereas Tubg2 knock-out mice developed normally and were fertile. It was proposed that γ-tubulin 1 represents ubiquitous γ-tubulin, while γ-tubulin 2 may have some specific functions and cannot substitute for γ-tubulin 1 deficiency in blastocysts. The molecular basis of the suggested functional difference between γ-tubulins remains unknown. Here we show that exogenous γ-tubulin 2 is targeted to centrosomes and interacts with γ-tubulin complex proteins 2 and 4. Depletion of γ-tubulin 1 by RNAi in U2OS cells causes impaired microtubule nucleation and metaphase arrest. Wild-type phenotype in γ-tubulin 1-depleted cells is restored by expression of exogenous mouse or human γ-tubulin 2. Further, we show at both mRNA and protein levels using RT-qPCR and 2D-PAGE, respectively, that in contrast to Tubg1, the Tubg2 expression is dramatically reduced in mouse blastocysts. This indicates that γ-tubulin 2 cannot rescue γ-tubulin 1 deficiency in knock-out blastocysts, owing to its very low amount. The combined data suggest that γ-tubulin 2 is able to nucleate microtubules and substitute for γ-tubulin 1. We propose that mammalian γ-tubulins are functionally redundant with respect to the nucleation activity
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