The catalytic subunit of the system L1 amino acid transporter (S<i>lc7a5</i>) facilitates nutrient signalling in mouse skeletal muscle

The System L1-type amino acid transporter mediates transport of large neutral amino acids (LNAA) in many mammalian cell-types. LNAA such as leucine are required for full activation of the mTOR-S6K signalling pathway promoting protein synthesis and cell growth. The SLC7A5 (LAT1) catalytic subunit of high-affinity System L1 functions as a glycoprotein-associated heterodimer with the multifunctional protein SLC3A2 (CD98). We generated a floxed Slc7a5 mouse strain which, when crossed with mice expressing Cre driven by a global promoter, produced Slc7a5 heterozygous knockout (Slc7a5+/-) animals with no overt phenotype, although homozygous global knockout of Slc7a5 was embryonically lethal. Muscle-specific (MCK Cre-mediated) Slc7a5 knockout (MS-Slc7a5-KO) mice were used to study the role of intracellular LNAA delivery by the SLC7A5 transporter for mTOR-S6K pathway activation in skeletal muscle. Activation of muscle mTOR-S6K (Thr389 phosphorylation) in vivo by intraperitoneal leucine injection was blunted in homozygous MS-Slc7a5-KO mice relative to wild-type animals. Dietary intake and growth rate were similar for MS-Slc7a5-KO mice and wild-type littermates fed for 10 weeks (to age 120 days) with diets containing 10%, 20% or 30% of protein. In MS-Slc7a5-KO mice, Leu and Ile concentrations in gastrocnemius muscle were reduced by ∼40% as dietary protein content was reduced from 30 to 10%. These changes were associated with >50% decrease in S6K Thr389 phosphorylation in muscles from MS-Slc7a5-KO mice, indicating reduced mTOR-S6K pathway activation, despite no significant differences in lean tissue mass between groups on the same diet. MS-Slc7a5-KO mice on 30% protein diet exhibited mild insulin resistance (e.g. reduced glucose clearance, larger gonadal adipose depots) relative to control animals. Thus, SLC7A5 modulates LNAA-dependent muscle mTOR-S6K signalling in mice, although it appears non-essential (or is sufficiently compensated by e.g. SLC7A8 (LAT2)) for maintenance of normal muscle mass

Honey bee foraging distance depends on month and forage type

To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other

Participation in and attitude towards the national immunization program in the Netherlands: data from population-based questionnaires

Contains fulltext : 108971.pdf (publisher's version ) (Open Access)BACKGROUND: Knowledge about the determinants of participation and attitude towards the National Immunisation Program (NIP) may be helpful in tailoring information campaigns for this program. Our aim was to determine which factors were associated with nonparticipation in the NIP and which ones were associated with parents' intention to accept remaining vaccinations. Further, we analyzed possible changes in opinion on vaccination over a 10 year period. METHODS: We used questionnaire data from two independent, population-based, cross-sectional surveys performed in 1995-96 and 2006-07. For the 2006-07 survey, logistic regression modelling was used to evaluate what factors were associated with nonparticipation and with parents' intention to accept remaining vaccinations. We used multivariate multinomial logistic regression modelling to compare the results between the two surveys. RESULTS: Ninety-five percent of parents reported that they or their child (had) participated in the NIP. Similarly, 95% reported they intended to accept remaining vaccinations. Ethnicity, religion, income, educational level and anthroposophic beliefs were important determinants of nonparticipation in the NIP. Parental concerns that played a role in whether or not they would accept remaining vaccinations included safety of vaccinations, maximum number of injections, whether vaccinations protect the health of one's child and whether vaccinating healthy children is necessary. Although about 90% reported their opinion towards vaccination had not changed, a larger proportion of participants reported to be less inclined to accept vaccination in 2006-07 than in 1995-96. CONCLUSION: Most participants had a positive attitude towards vaccination, although some had doubts. Groups with a lower income or educational level or of non-Western descent participated less in the NIP than those with a high income or educational level or indigenous Dutch and have been less well identified previously. Particular attention ought to be given to these groups as they contribute in large measure to the rate of nonparticipation in the NIP, i.e., to a greater extent than well-known vaccine refusers such as specific religious groups and anthroposophics. Our finding that the proportion of the population inclined to accept vaccinations is smaller than it was 10 years ago highlights the need to increase knowledge about attitudes and beliefs regarding the NIP

Variation in styles of rifting in the Gulf of California

Author Posting. © Nature Publishing Group, 2007. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 448 (2007): 466-469, doi:10.1038/nature06035.The rifting of continental lithosphere is a fundamental solid-earth process that leads to the formation of rifted continental margins and ocean basins. Understanding of this process comes from observations of the geometry of rifted margins and the magmatism resulting from rifting, which inform us about the strength of the lithosphere, the state of the underlying mantle, and the transition from rifting to seafloor spreading. Here we describe results from the PESCADOR seismic experiment in the southern Gulf of California and present the first crustal-scale images across conjugate margins of multiple segments within a single rift that has reached the stage of oceanic spreading. A surprisingly large variation in rifting style and magmatism is observed between these segments, from wide rifting with minor syn-rift magmatism to narrow rifting in magmatically robust segments. These differences encompass much of the variation observed across nearly all other non-end-member continental margins. The characteristics of magmatic endmember margins are typically explained in terms of mantle temperature. Our explanations for the variation in the Gulf of California, in contrast, invoke mantle depletion to account for wide, magma-poor rifting and mantle fertility and possibly the influence of sediments to account for robust rift and post-rift magmatism in the Gulf of California. These factors may vary laterally over small distances in regions that have transitioned from convergence to extension, as is the case for the Gulf of California and many other rifts.This work was funded by a grant from the U.S. NSF-MARGINS program

Multiple Dendritic Cell Populations Activate CD4+ T Cells after Viral Stimulation

Dendritic cells (DC) are a heterogeneous cell population that bridge the innate and adaptive immune systems. CD8α DC play a prominent, and sometimes exclusive, role in driving amplification of CD8+ T cells during a viral infection. Whether this reliance on a single subset of DC also applies for CD4+ T cell activation is unknown. We used a direct ex vivo antigen presentation assay to probe the capacity of flow cytometrically purified DC populations to drive amplification of CD4+ and CD8+ T cells following infection with influenza virus by different routes. This study examined the contributions of non-CD8α DC populations in the amplification of CD8+ and CD4+ T cells in cutaneous and systemic influenza viral infections. We confirmed that in vivo, effective immune responses for CD8+ T cells are dominated by presentation of antigen by CD8α DC but can involve non-CD8α DC. In contrast, CD4+ T cell responses relied more heavily on the contributions of dermal DC migrating from peripheral lymphoid tissues following cutaneous infection, and CD4 DC in the spleen after systemic infection. CD4+ T cell priming by DC subsets that is dependent upon the route of administration raises the possibility that vaccination approaches could be tailored to prime helper T cell immunity

Immunity against Neisseria meningitidis Serogroup C in the Dutch Population before and after Introduction of the Meningococcal C Conjugate Vaccine

Contains fulltext : 88187.pdf (publisher's version ) (Open Access)BACKGROUND: In 2002 a Meningococcal serogroup C (MenC) conjugate vaccine, with tetanus toxoid as carrier protein, was introduced in the Netherlands as a single-dose at 14 months of age. A catch-up campaign was performed targeting all individuals aged 14 months to 18 years. We determined the MenC-specific immunity before and after introduction of the MenC conjugate (MenCC) vaccine. METHODS AND FINDINGS: Two cross-sectional population-based serum banks, collected in 1995/1996 (n = 8539) and in 2006/2007 (n = 6386), were used for this study. The main outcome measurements were the levels of MenC polysaccharide(PS)-specific IgG and serum bactericidal antibodies (SBA) after routine immunization, 4-5 years after catch-up immunization or by natural immunity. There was an increasing persistence of PS-specific IgG and SBA with age in the catch-up immunized cohorts 4-5 years after their MenCC immunization (MenC PS-specific IgG, 0.25 microg/ml (95%CI: 0.19-0.31 microg/ml) at age 6 years, gradually increasing to 2.34 microg/ml,(95%CI: 1.70-3.32 microg/ml) at age 21-22 years). A comparable pattern was found for antibodies against the carrier protein in children immunized above 9 years of age. In case of vaccination before the age of 5 years, PS-specific IgG was rapidly lost. For all age-cohorts together, SBA seroprevalence (> or =8) increased from 19.7% to 43.0% in the pre- and post-MenC introduction eras, respectively. In non-immunized adults the SBA seroprevalence was not significantly different between the pre- and post-MenC introduction periods, whereas PS-specific IgG was significantly lower in the post-MenC vaccination (GMT, age > or =25 years, 0.10 microg/ml) era compared to the pre-vaccination (GMT, age > or =25 years, 0.43 microg/ml) era. CONCLUSION: MenCC vaccination administered above 5 years of age induced high IgG levels compared to natural exposure, increasing with age. In children below 14 months of age and non-immunized cohorts lower IgG levels were observed compared to the pre-vaccination era, whereas functional levels remained similar in adults. Whether the lower IgG poses individuals at increased risk for MenC disease should be carefully monitored. Large-scale introduction of a MenCC vaccine has led to improved protection in adolescents, but in infants a single-dose schedule may not provide sufficient protection on the long-term and therefore a booster-dose early in adolescence should be considered

Protection from Intracellular Oxidative Stress by Cytoglobin in Normal and Cancerous Oesophageal Cells

Cytoglobin is an intracellular globin of unknown function that is expressed mostly in cells of a myofibroblast lineage. Possible functions of cytoglobin include buffering of intracellular oxygen and detoxification of reactive oxygen species. Previous work in our laboratory has demonstrated that cytoglobin affords protection from oxidant-induced DNA damage when over expressed in vitro, but the importance of this in more physiologically relevant models of disease is unknown. Cytoglobin is a candidate for the tylosis with oesophageal cancer gene, and its expression is strongly down-regulated in non-cancerous oesophageal biopsies from patients with TOC compared with normal biopsies. Therefore, oesophageal cells provide an ideal experimental model to test our hypothesis that downregulation of cytoglobin expression sensitises cells to the damaging effects of reactive oxygen species, particularly oxidative DNA damage, and that this could potentially contribute to the TOC phenotype. In the current study, we tested this hypothesis by manipulating cytoglobin expression in both normal and oesophageal cancer cell lines, which have normal physiological and no expression of cytoglobin respectively. Our results show that, in agreement with previous findings, over expression of cytoglobin in cancer cell lines afforded protection from chemically-induced oxidative stress but this was only observed at non-physiological concentrations of cytoglobin. In addition, down regulation of cytoglobin in normal oesophageal cells had no effect on their sensitivity to oxidative stress as assessed by a number of end points. We therefore conclude that normal physiological concentrations of cytoglobin do not offer cytoprotection from reactive oxygen species, at least in the current experimental model

Regulation of Amyloid Precursor Protein Processing by the Beclin 1 Complex

Autophagy is an intracellular degradation pathway that functions in protein and organelle turnover in response to starvation and cellular stress. Autophagy is initiated by the formation of a complex containing Beclin 1 (BECN1) and its binding partner Phosphoinositide-3-kinase, class 3 (PIK3C3). Recently, BECN1 deficiency was shown to enhance the pathology of a mouse model of Alzheimer Disease (AD). However, the mechanism by which BECN1 or autophagy mediate these effects are unknown. Here, we report that the levels of Amyloid precursor protein (APP) and its metabolites can be reduced through autophagy activation, indicating that they are a substrate for autophagy. Furthermore, we find that knockdown of Becn1 in cell culture increases the levels of APP and its metabolites. Accumulation of APP and APP C-terminal fragments (APP-CTF) are accompanied by impaired autophagosomal clearance. Pharmacological inhibition of autophagosomal-lysosomal degradation causes a comparable accumulation of APP and APP-metabolites in autophagosomes. Becn1 reduction in cell culture leads to lower levels of its binding partner Pik3c3 and increased presence of Microtubule-associated protein 1, light chain 3 (LC3). Overexpression of Becn1, on the other hand, reduces cellular APP levels. In line with these observations, we detected less BECN1 and PIK3C3 but more LC3 protein in brains of AD patients. We conclude that BECN1 regulates APP processing and turnover. BECN1 is involved in autophagy initiation and autophagosome clearance. Accordingly, BECN1 deficiency disrupts cellular autophagy and autophagosomal-lysosomal degradation and alters APP metabolism. Together, our findings suggest that autophagy and the BECN1-PIK3C3 complex regulate APP processing and play an important role in AD pathology

Clinical development of new drug-radiotherapy combinations.

In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures include the use of radiotherapy, either as a single modality or combined with other treatments. Radiotherapy can provide enormous benefit to patients with cancer. In the past decade, significant technical advances, such as image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic radiotherapy, and proton therapy enable higher doses of radiotherapy to be delivered to the tumour with significantly lower doses to normal surrounding tissues. However, apart from the combination of traditional cytotoxic chemotherapy with radiotherapy, little progress has been made in identifying and defining optimal targeted therapy and radiotherapy combinations to improve the efficacy of cancer treatment. The National Cancer Research Institute Clinical and Translational Radiotherapy Research Working Group (CTRad) formed a Joint Working Group with representatives from academia, industry, patient groups and regulatory bodies to address this lack of progress and to publish recommendations for future clinical research. Herein, we highlight the Working Group's consensus recommendations to increase the number of novel drugs being successfully registered in combination with radiotherapy to improve clinical outcomes for patients with cancer.National Institute for Health ResearchThis is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/nrclinonc.2016.7

Genome-wide association study identifies Sjögren’s risk loci with functional implications in immune and glandular cells

Sjögren’s disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjögren’s cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands.Research reported in this publication was supported by the National Institutes of Health (NIH): R01AR073855 (C.J.L.), R01AR065953 (C.J.L.), R01AR074310 (A.D.F.), P50AR060804 (K.L.S.), R01AR050782 (K.L.S), R01DE018209 (K.L.S.), R33AR076803 (I.A.), R21AR079089 (I.A.); NIDCR Sjögren’s Syndrome Clinic and Salivary Disorders Unit were supported by NIDCR Division of Intramural Research at the National Institutes of Health funds - Z01-DE000704 (B.W.); Birmingham NIHR Biomedical Research Centre (S.J.B.); Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2155 – Projektnummer 390874280 (T.W.); Research Council of Norway (Oslo, Norway) – Grant 240421 (TR.R.), 316120 (M.W-H.); Western Norway Regional Health Authority (Helse Vest) – 911807, 912043 (R.O.); Swedish Research Council for Medicine and Health (L.R., G.N., M.W-H.); Swedish Rheumatism Association (L.R., G.N., M.W-H.); King Gustav V’s 80-year Foundation (G.N.); Swedish Society of Medicine (L.R., G.N., M.W-H.); Swedish Cancer Society (E.B.); Sjögren’s Syndrome Foundation (K.L.S.); Phileona Foundation (K.L.S.). The Stockholm County Council (M.W-H.); The Swedish Twin Registry is managed through the Swedish Research Council - Grant 2017-000641. The French ASSESS (Atteinte Systémique et Evolution des patients atteints de Syndrome de Sjögren primitive) was sponsored by Assistance Publique-Hôpitaux de Paris (Ministry of Health, PHRC 2006 P060228) and the French society of Rheumatology (X.M.).publishedVersio