Divergent effects of peripheral and global neuropeptide Y deletion

Objectives:Neuropeptide Y (NPY) is involved in the coordination of bone mass and adiposity. However, multiple NPY sources exist and their individual contribution to the skeleton and adiposity not known. The objectives of our study were to evaluate the effects of peripheral mesenchymal derived NPY to the skeleton and adiposity and to compare them to the global NPY^KO model.Methods:To study the role of mesenchymal-derived NPY, we crossed conditional NPY (NPY^fl/fl) mice with Prx1cre to generate PrxNPY^KO mice. The bone phenotype was assessed using micro-CT. The skeletal phenotype of PrxNPY^KO mice was subsequently compared to global NPY^KO model. We evaluated body weight, adiposity and functionally assessed the feeding response of NPY neurons to determine whether central NPY signaling was altered by Prx1cre.Results:We identified the increase in cortical parameters in PrxNPY^KO mice with no changes to cancellous bone. This was the opposite phenotype to global NPY^KO mice generated from the same conditional allele. Male NPY^KO mice have increased adiposity, while PrxNPY^KO mice showed no difference, demonstrating that local mesenchymal-derived NPY does not influence adiposity.Conclusion:NPY mediates both positive and negative effects on bone mass via separate regulatory pathways. Deletion of mesenchymal-derived NPY had a positive effect on bone mass.     

Lack of DNA polymerase μ affects the kinetics of DNA double-strand break repair and impacts on cellular senescence

The specialised DNA polymerase μ (pol μ) affects a sub-class of immunoglobulin genes rearrangements and haematopoietic development in vivo. These effects appear linked to double-strand breaks (DSBs) repair, but it is still unclear how and to what extent pol μ intervenes in this process. Using high-resolution quantitative imaging of DNA damage in irradiated wild-type and pol μ^?/? mouse embryonic fibroblasts (MEFs) we show that lack of pol μ results in delayed DSB repair kinetics and in persistent DNA damage. DNA damage triggers cellular senescence, and this response is thought to suppress cancer. Independent investigations either report or not a proliferative decline for MEFs lacking pol μ. Here we show pronounced senescence in pol μ^?/? MEFs, associated with high levels of the tumor-suppressor p16^INK4A and the DNA damage response kinase CHK2. Importantly, cellular senescence is induced by culture stress and exacerbated by low doses of irradiation in pol μ^?/? MEFs. We also found that low doses of irradiation provoke delayed immortalisation in MEFs lacking pol μ. Pol μ^?/? MEFs thus exhibit a robust anti-proliferative defence in response to irreparable DNA damage. These findings indicate that sub-optimal DSB repair, due to the absence of an auxiliary DNA damage repair factor, can impact on cell fitness and thereby on cell fate.     

Discovery of TAK-960: An orally available small molecule inhibitor of polo-like kinase 1 (PLK1)

Using structure-based drug design, we identified and optimized a novel series of pyrimidodiazepinone PLK1 inhibitors resulting in the selection of the development candidate TAK-960. TAK-960 is currently undergoing Phase I evaluation in adult patients with advanced solid malignancies.     

The Moderated Relationship of Appearance Valence on Appearance Self Consciousness: Development and Testing of New Measures of Appearance Schema Components

This paper describes the creation and psychometric properties of two independent measures of aspects of appearance schematicity – appearance salience and valence, assessed by the CARSAL and CARVAL, and their relation to appearance self-consciousness. Five hundred and ninety two participants provided data in a web based task. The results demonstrate the sound psychometric properties of both scales. This was demonstrated by good item total characteristics, good internal reliability of each scale, and the independence of the two scales shown through principal components analysis. Furthermore, the scales show independent and moderated relationships with valid measures of appearance related psychosocial distress. Negatively valenced appearance information was associated with increased appearance self-consciousness. More crucially, the impact of negative valence on appearance self-consciousness was exacerbated by the moderating effect increased salience of appearance.     

Sub-optimal delivery of intermittent preventive treatment for malaria in pregnancy in Nigeria: influence of provider factors

ABSTRACT: BACKGROUND: The level of access to intermittent preventive treatment for malaria in pregnancy (IPTp) in Nigeria is still low despite relatively high antenatal care coverage in the study area. This paper presents information on provider factors that affect the delivery of IPTp in Nigeria. METHODS: Data were collected from heads of maternal health units of 28 public and six private health facilities offering antenatal care (ANC) services in two districts in Enugu State, south-east Nigeria. Provider knowledge of guidelines for IPTp was assessed with regard to four components: the drug used for IPTp, time of first dose administration, of second dose administration, and the strategy for sulphadoxine-pyrimethamine (SP) administration (directly observed treatment, DOT). Provider practices regarding IPTp and facility-related factors that may explain observations such as availability of SP and water were also examined. RESULTS: Only five (14.7%) of all 34 providers had correct knowledge of all four recommendations for provision of IPTp. None of them was a private provider. DOT strategy was practiced in only one and six private and public providers respectively. Overall, 22 providers supplied women with SP in the facility and women were allowed to take it at home. The most common reason for doing so amongst public providers was that women were required to come for antenatal care on empty stomachs to enhance the validity of manual fundal height estimation. Two private providers did not think it was necessary to use the DOT strategy because they assumed that women would take their drugs at home. Availability of SP and water in the facility, and concerns about side effects were not considered impediments to delivery of IPTp. CONCLUSION: There was low level of knowledge of the guidelines for implementation of IPTp by all providers, especially those in the private sector. This had negative effects such as nonpractice of DOT strategy by most of the providers, which can lead to low levels of adherence to IPTp and ineffectiveness of IPTp. Capacity development and regular supportive supervisory visits by programme managers could help improve the provision of IPTp.     

Duplication and paralog sorting of RPB2 and RPB1 genes in core eudicots

RPB1 and RPB2, which encode the largest and second largest subunits of RNA polymerase II, respectively, are essential single copy genes in fungi, animals and most plants. Two paralogs of the RPB2 gene have been found in some groups of angioperms [Oxelman, B., Yoshikawa, N., McConaughy, B.L., Luo, J., Denton, A.L., Hall, B.D., 2004. RPB2 gene phylogeny in flowering plants, with particular emphasis on asterids. Mol. Phylogenet. Evol. 32, 462-479]. Here, we report the results of experiments designed to identify the evolutionary origin of the RPB2 duplicate copies. Through careful sampling and phylogenetic analysis, we were able to construct the RPB2 gene tree in angiosperms and infer the phylogenetic positions of the gene duplication and gene loss events that occurred. Our study shows that an RPB2 gene duplication occurred early in core eudicot evolution, at or near the time of the Buxaceae/Trochodendraceae divergence. Subsequently, multiple gene duplication and paralog sorting events happened independently in different core eudicot taxa. Differential expression of the two RPB2 gene paralogs may explain the preservation of both paralogs in the asterids. One gene (RPB2-i) accounts for most of the RPB2 mRNA made in the flower organs while the other gene (RPB2-d) is predominantly used in the vegetative tissues. We also found two paralogs of the RPB1 gene in some core eudicot species. The RPB1 gene duplication occurred before core eudicot divergence, around the time of RPB2 gene duplication. Several independent RPB1 paralog sorting events happened in different core eudicot taxa; their occurrence was independent of the RPB2 paralog sorting events. Our results suggest that a polyploidization event happened at or near the time of the Buxaceae/Trochodendraceae divergence. We propose that this polyploidization and the partial diploidization processes thereafter may have been the driving force of core eudicot radiation.     

A comparison of immobilized pH gradient isoelectric focusing and strong-cation-exchange chromatography as a first dimension in shotgun proteomics

Recently, we have developed a high-resolution two-dimensional separation strategy for the analysis of complex peptide mixtures. This methodology employs isoelectric focusing of peptides on immobilized pH gradient (IPG) gels in the first dimension, followed by reversed-phase chromatography in the second dimension, and subsequent tandem mass spectrometry analysis. The traditional approach to this mixture problem employs strong-cation-exchange (SCX) chromatography in the first dimension. Here, we present a direct comparison of these two first-dimensional techniques using complex protein samples derived from the testis of Rattus norvegicus. It was found that the use of immobilized pH gradients (narrow range pH 3.5-4.5) for peptide separation in the first dimension yielded 13% more protein identifications than the optimized off-line SCX approach (employing the entire pI range of the sample). In addition, the IPG technique allows for a much more efficient use on mass spectrometer analysis time. Separation of a tryptic digest derived from a rat testis sample on a narrow range pH gradient (over the 3.5-4.5 pH range) yielded 7626 and 2750 peptides and proteins, respectively. Peptide and protein identification was performed with high confidence using SEQUEST in combination with a data filtering program employing pI and statistical based functions to remove false-positives from the data.