Description: The transit of RV SONNE from Las Palmas (departure: 11.12.2021) to Guayaquil, Ecuador (arrival: 11.01.2022) is directly related to the international collaborative project SO287-CONNECT of GEOMAR in cooperation with Hereon and the University of Bremen, supported by the German Federal Ministry of Education and Research (BMBF) between October 15 2021 and January 15 2024. The research expedition was conducted to decipher the coupling of biogeochemical and ecological processes and their influence on atmospheric chemistry along the transport pathway of water from the upwelling zones off Africa into the Sargasso Sea and further to the Caribbean and the equatorial Pacific. Nutrient-rich water rises from the deep and promotes the growth of plant and animal microorganisms, and fish at the ocean surface off West Africa. The North Equatorial Current water carries the water from the upwelling, which contains large amounts of organic material across the Atlantic to the Caribbean, supporting bacterial activity along the way. But how the nutritious remnants of algae and other substances are processed on their long journey, biochemically transformed, decomposed into nutrients and respired to carbon dioxide, has so far only been partially investigated. Air, seawater and particles were sampled in order to provide new details about the large cycles of carbon and nitrogen, but also of many other elements such as oxygen, iodine, bromine and sulfur. Inorganic and organic bromine and iodine compounds are generally emitted naturally from the ocean into the atmosphere, promote cloud formation and affect climate, and some even reach the stratosphere where they contribute to ozone depletion. We measured how much of these compounds are released from the ocean, and at what locations and how they are transformed in the ocean and in the atmosphere. Sargassum algae, which have become a nuisance on beaches in the western and eastern Atlantic, support life and contribute to carbon cycling in the middle of the Atlantic, the Sargasso Sea and in the Caribbean, while their contribution to halogen cycling and marine bromine and iodine emissions was previously unknown. We investigated the influence of various natural parameters such as temperature and solar radiation on the biogeochemical transformation processes in order to understand the influence of climate change on these processes in incubation experiments with seawater and algae. We investigated how anthropogenic signals such as shipping traffic influence the nitrogen and sulphur cycle in the ocean, as well as the impact of nitrogen oxides from ship exhaust and sulphurous, acidic and dirty water from purification systems on organisms and biochemical processes. Plastic debris was sampled from the surface waters to investigate its contribution to global biogeochemical transformation processes. The working hypotheses of the research program were:  Bioavailability of dissolved organic carbon in surface waters decreases along the productivity gradient and transport pathway from the Eastern to the Western Tropical North Atlantic.  Nutrient gradients from East to West constrain the microbial utilization of organic matter- contributing to an accumulation of C-rich organic matter due to a) limited mineralization and b) enhanced exudation- also leading to gel-like particles accumulation in the western tropical North Atlantic and Sargasso Sea.  Tropospheric and stratospheric ozone are strongly impacted by biogeochemical and ecological processes occurring around and in the NA gyre system related to marine iodine and bromine cycles.  The long-range transport of natural and anthropogenic organic matter in water and of gases and aerosols in the air impact carbon-export, biogeochemical cycles in the water column, and the release of gases and particles from the ocean significantly. 4 SONNE -Berichte, SO287, Las Palmas - Guayaquil, 11.12.2021 - 11.01.202 The data and samples obtained specifically target carbon, nutrient and halogen cycling, the composition of phytoplankton, bacteria, the transport and sequestration of macro algae and the air-sea exchange processes of climate relevant gases and aerosols. The influence of ecological and transport processes, as well as anthropogenic impacts on the North Atlantic gyre system, specifically in the Sargasso Sea and the influence of ship emissions throughout the Atlantic towards the west and into the Pacific will be investigated with the data.

Description: Human glycolipid transfer protein (hsGLTP) forms the prototypical GLTP fold and is characterized by a broad transfer selectivity for glycosphingolipids (GSLs). The GLTP mutation D48V near the `portal entrance' of the glycolipid binding site has recently been shown to enhance selectivity for sulfatides (SFs) containing a long acyl chain. Here, nine novel crystal structures of hsGLTP and the SF-selective mutant complexed with short-acyl-chain monoSF and diSF in different crystal forms are reported in order to elucidate the potential functional roles of lipid-mediated homodimerization. In all crystal forms, the hsGLTP–SF complexes displayed homodimeric structures supported by similarly organized intermolecular interactions. The dimerization interface always involved the lipid sphingosine chain, the protein C-terminus (C-end) and α-helices 6 and 2, but the D48V mutant displayed a `locked' dimer conformation compared with the hinge-like flexibility of wild-type dimers. Differences in contact angles, areas and residues at the dimer interfaces in the `flexible' and `locked' dimers revealed a potentially important role of the dimeric structure in the C-end conformation of hsGLTP and in the precise positioning of the key residue of the glycolipid recognition centre, His140. ΔY207 and ΔC-end deletion mutants, in which the C-end is shifted or truncated, showed an almost complete loss of transfer activity. The new structural insights suggest that ligand-dependent reversible dimerization plays a role in the function of human GLTP.

Description: Background: Psoriatic Arthritis (PsA) is estimated to occur in 10-15% of people with psoriasis and accounts for 13% of people attending early arthritis clinics. With an increasing awareness of the poor outcomes associated with PsA and the availability of new effective, but costly, treatments, there is an urgent need to research the optimal treatment for patients with PsA. The aim of the TICOPA study is to establish whether, in treatment naive early PsA patients, "tight control" intensive management with protocol driven therapies and pre-defined objective targets for treatment can improve clinical outcome compared to standard care alone. Methods: TICOPA is a UK multicentre, open-label, randomised controlled, parallel group trial of 206 patients with early PsA. Patients will be randomised on a 1:1 basis to receive either standard care (12 weekly review) or intensive management (4 weekly review) for a period of 48 weeks. Patients assigned to the intensive management group will follow a strict treatment protocol whereby dose continuation/escalation is determined through the objective assessment of the minimal disease activity (MDA) criteria. Patients assigned to the standard care group will have treatment prescribed as felt appropriate by the treating clinician, with no set protocol. The primary objective of the trial is to compare intensive management with standard care in terms of the proportion of patients achieving an ACR 20 response at 48 weeks post-randomisation, in order to determine whether intensive management has superior clinical efficacy. Key secondary outcomes include ACR 50 and 70, PASI 75 and X-ray Van der Heijde score at 48 weeks post-randomisation along with cost-effectiveness at 12, 24 and 28 weeks.DiscussionThe TICOPA trial will provide direct evidence as to whether the use of early and intensive treatment in PsA in routine clinical care leads to an improvement in patients' disease activity and a reduction in radiological joint damage.Trial registration: ISRCTN30147736NCT01106079

Description: Nature Reviews Rheumatology 11, 131 (2015). doi:10.1038/nrrheum.2014.210 Authors: Chrysothemis C. Brown & Lucy R. Wedderburn Can a patient's genotype provide insight into the mechanistic basis of autoimmune disease? A study integrating epigenetic data with finely mapped disease-associated variants sheds light on how noncoding variants might alter gene expression within specific immune cells, and hints at new possibilities for individualizing treatment of autoimmune rheumatic disorders.