Quantitative proteomics of a B12 -dependent alga grown in coculture with bacteria reveals metabolic tradeoffs required for mutualism

The unicellular green alga Lobomonas rostrata requires an external supply of vitamin B12 (cobalamin) for growth, which it can obtain in stable laboratory cultures from the soil bacterium Mesorhizobium loti in exchange for photosynthate. We investigated changes in protein expression in the alga that allow it to engage in this mutualism. We used quantitative isobaric tagging (iTRAQ) proteomics to determine the L. rostrata proteome grown axenically with B12 supplementation or in coculture with M. loti. Data are available via ProteomeXchange (PXD005046). Using the related Chlamydomonas reinhardtii as a reference genome, 588 algal proteins could be identified. Enzymes of amino acid biosynthesis were higher in coculture than in axenic culture, and this was reflected in increased amounts of total cellular protein and several free amino acids. A number of heat shock proteins were also elevated. Conversely, photosynthetic proteins and those of chloroplast protein synthesis were significantly lower in L. rostrata cells in coculture. These observations were confirmed by measurement of electron transfer rates in cells grown under the two conditions. The results indicate that, despite the stability of the mutualism, L. rostrata experiences stress in coculture with M. loti, and must adjust its metabolism accordingly.The work in this manuscript was supported by funding from the Biotechnology and Biological Sciences Research Council (BBSRC) of the UK (grant BB/I013164/1, a CASE studentship for M.B.C. joint with PML Applications Ltd, Plymouth, UK, and a DTP studentship for F.B.); an EU FP7 Marie Curie ITN Photo.Comm, no. 317184 for U.J.K.; Engineering and Physical Science Research Council (EPSRC) grant EP/E036252/1; and the Natural Environment Research Council (NERC) grant NE/J024767/1

Chemoattractant Receptor Homologous to the T Helper 2 Cell (CRTH2) Is Not Expressed in Human Amniocytes and Myocytes

BACKGROUND: 15-deoxy-Δ 12,14- Prostaglandin J2 (15dPGJ2) inhibits Nuclear factor kappa B (NF-κB) in human myocytes and amniocytes and delays inflammation induced preterm labour in the mouse. 15dPGJ2 is a ligand for the Chemoattractant Receptor Homologous to the T helper 2 cell (CRTH2), a G protein-coupled receptor, present on a subset of T helper 2 (Th2) cells, eosinophils and basophils. It is the second receptor for Prostaglandin D2, whose activation leads to chemotaxis and the production of Th2-type interleukins. The cellular distribution of CRTH2 in non-immune cells has not been extensively researched, and its identification at the protein level has been limited by the lack of specific antibodies. In this study we explored the possibility that CRTH2 plays a role in 15dPGJ2-mediated inhibition of NF-κB and would therefore represent a novel small molecule therapeutic target for the prevention of inflammation induced preterm labour. METHODS: The effect of a small molecule CRTH2 agonist on NF-κB activity in human cultured amniocytes and myocytes was assessed by detection of p65 and phospho-p65 by immunoblot. Endogenous CRTH2 expression in amniocytes, myocytes and peripheral blood mononuclear cells (PBMCs) was examined by PCR, western analysis and flow cytometry, with amniocytes and myocytes transfected with CRTH2 acting as a positive control in flow cytometry studies. RESULTS: The CRTH2 agonist had no effect on NF-κB activity in amniocytes and myocytes. Although CRTH2 mRNA was detected in amniocytes and myocytes, CRTH2 was not detectable at the protein level, as demonstrated by western analysis and flow cytometry. 15dPGJ2 inhibited phospho-65 in PBMC'S, however the CRTH2 antagonist was not able to attenuate this effect. In conclusion, CRTH2 is not expressed on human amniocytes or myocytes and plays no role in the mechanism of 15dPGJ2-mediated inhibition of NF-κB

Spondyloarthropathies

The spondyloarthropathies include ankylosing spondylitis and psoriatic arthritis. The hallmark clinical features are inflammatory spinal disease, dactylitis, and enthesitis, together with an asymmetrical oligoarthritis, often of the lower limbs. Psoriaform skin and nail changes are also frequently seen, and, less commonly, but characteristically, a mutilating arthritis with severe deformity of the toes. These unique features often allow a diagnosis to be made purely on clinical examination of the lower limbs. However, these features also provide challenges for local treatments as skin disease may complicate the use of orthoses and percutaneous steroid injections. However, the importance of mechanical factors in the pathogenesis of these disorders almost mandates a combined mechanical and pharmacological approach to treatment

Evaluating the Cutaneous Involvement in Scleroderma: Torsional Stiffness Revisited

Objective: The pace, progression and extent of the skin lesions in scleroderma may parallel the risk of new internal organ involvement and the progression of existing internal lesions. Accurate assessment of cutaneous change permits an evaluation of patient prognosis and the response to therapy. The aim of this study was to assess a simple device for measuring skin stiffness for its ability to measure sclerodermatous skin in a quantitative and reproducible manner. Materials and methods: Torsional skin stiffness was measured in 56 normal subjects and 42 scleroderma patients (31 of whom had the limited form and nine the diffuse form, and two had mixed connective tissue disease). Data for the scleroderma patients were compared with data obtained by the use of the modified Rodnan clinical skin scoring technique. Intraclass correlation coefficients (ICCs) were calculated as a measure of intraobserver and interobserver variability. Results: For the left and right hands respectively, the ICCs for intraobserver variability were 0.908 and 0.906 and those for interobserver variability were 0.871 and 0.628. There was a significant difference in mean angular rotation obtained by normal subjects compared with scleroderma patients (15.1 vs 11.3[degrees], P<0.001). There was a significant difference in the angular rotation with increasing severity of skin involvement (skin score 0, median rotation 16.3[degrees]; score 1, 10.5[degrees]; score 2, 8.5[degrees]; score 3, 8.0[degrees]; P<0.00001). Conclusions: The measurements obtained with the skin stiffness device are highly reproducible and are consistent with the current clinical method of assessment of skin involvement. The significant difference in angular rotation obtained by normal subjects and scleroderma patients indicates that the device can distinguish normal from sclerodermatous skin. The torsional stiffness measurements derived from the device may also be useful in longitudinal studies

Provincial Development in China: Lessons from EU Regional Policy Experience

This article evaluates and compares regional development in the Chinese provinces and in the regions of the European Union (EU) countries. Development efforts in southern Italy, northeast England and eastern Germany are reviewed along with EU, Community-wide regional development programmes. Equity concerns suggest promotion of regional policy, but the pursuit of maximum national economic growth would avoid it, since it sacrifices some economic growth. The impact of foreign direct investment (FDI) and domestic investments on individual Chinese provinces is compared with their impact in Europe. There is an implicit contrast between public sector regional development programs and more effective private foreign direct investments.Regional economic development, European Union, FDI, economic growth, regional development programs, lagging regions,

Calmodulin regulates human ether à go-go 1 (hEAG1) potassium channels through interactions of the eag-domain with the cyclic nucleotide binding homology domain

The ether à go-go family of voltage-gated potassium channels is structurally distinct. The N-terminus contains an eag domain (eagD) that contains a Per-Arnt-Sim (PAS) domain that is preceded by a conserved sequence of 25-27 amino acids known as the PAS-cap. The C-terminus contains a region with homology to cyclic nucleotide binding domains (cNBHD), which is directly linked to the channel pore. The human EAG1 (hEAG1) channel is remarkably sensitive to inhibition by intracellular calcium (Ca²⁺ᵢ) through binding of Ca²⁺-calmodulin to three sites adjacent to the eagD and cNBHD. Here, we show that the eagD and cNBHD interact to modulate Ca²⁺-calmodulin as well as voltage-dependent gating. Sustained elevation of Ca²⁺ᵢ resulted in an initial profound inhibition of hEAG1 currents, which was followed by a phase when current amplitudes partially recovered, but activation gating was slowed and shifted to depolarized potentials. Deletion of either the eagD or cNBHD abolished the inhibition by Ca²⁺ᵢ. However, deletion of just the PAS-cap resulted in a >15-fold potentiation in response to elevated Ca²⁺ᵢ. Mutations of residues at the interface between the eagD and cNBHD have been linked to human cancer. E600 on the cNBHD, when substituted with residues with a larger volume, resulted in hEAG1 currents that were profoundly potentiated by Ca²⁺ᵢ in a manner similar to the ΔPAS-cap mutant. These findings provide the first evidence that eagD and cNBHD interactions are regulating Ca²⁺-dependent gating and indicate that the binding of the PAS-cap with the cNBHD is required for the closure of the channels upon CaM binding

Impact of clinical domains other than arthritis on composite outcomes in psoriatic arthritis: comparison of treatment effects in the SEAM-PsA trial

Objective We used the Study of Etanercept And Methotrexate in Combination or as Monotherapy in Subjects with Psoriatic Arthritis (SEAM-PsA) data set to examine the impact of presence of enthesitis, dactylitis, nail disease and/or psoriasis on treatment response in patients with early psoriatic arthritis (PsA).Methods This post hoc analysis evaluated the effect of baseline Spondyloarthritis Research Consortium of Canada (SPARCC) Enthesitis Index (EI), Leeds Enthesitis Index (LEI), Leeds Dactylitis Index (LDI), modified Nail Psoriasis Severity Index (mNAPSI) scores and body surface area (BSA) on composite outcomes of minimal disease activity (MDA) responses, Psoriatic Arthritis Disease Activity Score (PASDAS) low disease activity (LDA), PASDAS changes and Good Responses and Disease Activity Index for Psoriatic Arthritis (DAPSA) scores at Week 24.Results Overall, 851 patients completed the SEAM-PsA trial and were included in the analysis. Baseline enthesitis (SPARCC EI&gt;0 vs SPARCC EI=0 or LEI&gt;0 vs LEI=0) was not associated with improved outcomes. Baseline dactylitis (LDI&gt;0 vs LDI=0) was positively associated with improved MDA (OR: 1.4, p=0.0457), PASDAS LDA (OR: 1.8, p=0.0014) and Good Responses (OR: 1.6, p=0.0101) and greater reductions in PASDAS (estimate: –0.9, p&lt;0.0001) and DAPSA scores (estimate: –3.8, p=0.0155) at Week 24. Similarly, baseline nail disease (mNAPSI &gt;1 vs mNAPSI≤1) was positively associated with improved MDA (OR: 1.8, p=0.0233) and PASDAS LDA (OR: 1.8, p=0.0168) responses and greater reduction in PASDAS (estimate: –0.7, p=0.0005) at Week 24.Conclusions Results from our analysis suggest that presence of dactylitis and nail disease, but not enthesitis, are associated with improved outcomes in patients with early PsA who were treated with methotrexate and/or etanercept

Transnational Corporations and Repression of Political Rights and Civil Liberties: An Empirical Analysis

Transnational Corporations are often accused by non-governmental organisations of ignoring fundamental democratic rights, such as civil liberties and political rights, in the countries of their investments. This paper attempts to explore empirically the complex relationship between foreign investment and democracy in a systematic way, using different econometric techniques. In contrast to the public discussion over recent years and the view held by non-governmental organisations, the results show that enhanced democratic rights are associated with higher foreign investment in the 1990s. Interestingly, this positive link does not hold for the 1970s and 1980s, when a substantial portion of foreign investment went to countries with repressive governments. Copyright WWZ and Helbing & Lichtenhahn Verlag AG 2004.