Bringing Molecules Together: Synergistic Coadsorption at Dopant Sites of Single Atom Alloys.

Bringing molecules together on a catalytic surface is a prerequisite for bimolecular and recombination reactions. However, in the absence of attractive interactions between reactants, such as hydrogen bonds, this poses a challenge. In contrast, based on density functional theory, we show that coadsorption at active sites of single-atom alloys (SAAs) is favored and that coadsorption is a general phenomenon observed for catalytically relevant adsorbates on a broad range of SAAs under temperature and pressure conditions commonly employed for catalysis. Dopants located in both terrace sites and in step edge defects exhibit a preference for coadsorption, displaying similar periodic trends. Using kinetic Monte Carlo simulations, we compare the reactivity of a model reaction on both a pure metal and an SAA and show that the preference for coadsorption significantly alters the overall reaction energy profile, even when the barriers for the rate-determining elementary step are identical. In our models, the coadsorption preference enhances the catalytic activity of the SAA surface by several orders of magnitude compared to the pure metal. We also report infrared (IR) spectroscopic signatures of coadsorption, which facilitate experimental detection. Analysis reveals that in these systems repulsive lateral interactions between nearby molecules are more than compensated for by the enhanced binding at dopant sites. Among the broad range of systems considered, SAAs containing early transition metals (TMs) exhibit the strongest coadsorption preference, which can be rationalized by assuming the existence of an optimal number of electrons involved in binding. The strong coadsorption preference, together with facile product desorption from early TMs, renders these systems attractive candidates for catalysis. Moreover, these SAAs could open new routes for reduction reactions because coadsorption with hydrogen is favored.

Achieving Digital Catalysis: Strategies for Data Acquisition, Storage and Use.

Heterogeneous catalysis is an important area of research that generates data as intricate as the phenomenon itself. Complexity is inherently coupled to the function of the catalyst and advance in knowledge can only be achieved if this complexity is adequately captured and accounted for. This requires integration of experiment and theory, high data quality and quality control, close interdisciplinary collaboration, and sharing of data and metadata, which is facilitated by the application of joint data management strategies. This Viewpoint Article first discusses the potential of a digital transition in catalysis research. Then, a summary of the current status in terms of data infrastructure in heterogeneous catalysis is presented, defining the various types of (meta-) data, from catalyst synthesis to functional analysis. Finally, an already implemented working concept for local data acquisition and storage is introduced and the benefits and further development directions for catalysis data use and sharing are discussed.

Relative versus absolute RNA quantification: a comparative analysis based on the example of endothelial expression of vasoactive receptors.

BACKGROUND: In the present study, two distinct PCR methods were used for the quantification of genetic material and their results were compared: real-time-PCR (qPCR; relative quantification) and droplet digital PCR (ddPCR; absolute quantification). The comparison of the qPCR and the ddPCR was based on a stimulation approach of microvascular endothelial cells in which the effect of a pro-inflammatory milieu on the expression of vasoactive receptors was investigated. RESULTS: There was consistency in directions of effects for the majority of genes tested. With regard to the indicated dimension of the effects, the overall picture was more differentiated. It was striking that deviations were more pronounced if the measured values were on the extreme edges of the dynamic range of the test procedures. CONCLUSIONS: To obtain valid and reliable results, dilution series are recommended, which should be carried out initially. In case of ddPCR the number of copies per µl should be adjusted to the low three-digit range. With regard to qPCR it is essential that the stability and reliability of the reference genes used is guaranteed. Here, ddPCR offers the advantage that housekeeping genes are not required. Furthermore, an absolute quantification of the sample can be easily performed by means of ddPCR. Before using ddPCR, however, care should be taken to optimize the experimental conditions. Strict indications for this methodology should also be made with regard to economic and timing factors.

CD96 expression determines the inflammatory potential of IL-9-producing Th9 cells.

Recent findings demonstrated proinflammatory functions of interleukin (IL)-9-producing T helper type (Th) 9 cells in the pathogenesis of intestinal bowel diseases (IBDs). However, also antiinflammatory properties have been ascribed to Th9 cells, pointing to a functional heterogeneity. To dissect the specific expression pattern and, especially, diversity of murine antigen-specific Th9 cells, we applied single cell transcription profiling. Th9 cells displayed reduced expression of typical activation markers, such as Cd40 ligand and Cd96, whereas expression of Cd25 and Cd83 was increased compared with other Th subsets. Importantly, we identified two subsets of Th9 cells differing above all in their CD96 expression. The heterogeneous CD96 expression was specific for Th9 cells and not observed for other Th subtypes, such as Th1 cells. Lower CD96 expression was also observed in human IL-9+ compared with IFN-γ+ T cells. Although Il9 was highly transcribed by all Th9 cells, IL-9 mRNA and protein expression was increased in CD96low cells. Transfer of CD96low Th9 cells into recombination activating gene 1-deficient (Rag1-/- ) mice caused severe weight loss, intestinal and colonic inflammation, and destruction of allogeneic skin grafts and thus showed high inflammatory potential. This was associated with their expansion and tissue accumulation. Contrastingly, CD96high Th9 cells did not cause colitis and showed reduced expansion and migratory potential. Blockade of CD96 completely restored the expansion and inflammatory properties of CD96high Th9 cells. Collectively, our data suggest an inhibitory role for the cosignaling receptor CD96 in Th9 cells, raising new opportunities in the treatment of IL-9-associated inflammations such as IBD.

The Reaction of CO2 with a Borylnitrene: Formation of an 3-Oxaziridinone.

The reaction of a borylnitrene with carbon dioxide is studied under cryogenic matrix isolation conditions. Photogenerated CatBN (Cat=catecholato) reacts with CO2 under formation of the cycloaddition product CatBNCO2 , a 3-oxaziridinone derivative, after photoexcitation (>550 nm). The product shows Fermi resonances between the CO stretching and ring deformation modes that cause unusual 13 C and 18 O isotopic shifts. A computational analysis of the 3-oxaziridinone shows this cyclic carbamate to be less strained than an α-lactone or an α-lactame.

Unusual Nitrene Oxidation Product Formation by Metathesis Involving the Dioxygen O-O and Borylnitrene B-N Bonds.

The reaction of dioxygen with nitrenes can have significant energy barriers, although both reactants are triplet diradicals and the formation of nitroso-O-oxides is spin-allowed. By means of matrix-isolation infrared spectroscopy in solid argon, nitrogen, and neon, and through high-level computational quantum chemistry, it is shown herein that a 3-nitreno-1,3,2-benzodioxaborole CatBN (Cat=catecholato) reacts with dioxygen under cryogenic conditions thermally at temperatures as low as 7 K to produce two distinct products, an anti-nitroso-O-oxide and a nitritoborane CatBONO. The computed barriers for the formation of nitroso-O-oxide isomers are very low. Whereas anti-nitroso-O-oxide is kinetically trapped, its bisected isomer has a very low barrier for metathesis, yielding the CatBO+NO radicals in a strongly exothermic reaction; these radicals can combine under matrix-isolation conditions to give nitritoborane CatBONO. The trapped isomer, anti-nitroso-O-oxide, can form the nitritoborane CatBONO only after photoexcitation, possibly involving isomerization to the bisected isomer of anti-nitroso-O-oxide.

Inotropic agents and vasodilator strategies for the treatment of cardiogenic shock or low cardiac output syndrome.

BACKGROUND: Cardiogenic shock (CS) and low cardiac output syndrome (LCOS) are potentially life-threatening complications of acute myocardial infarction (AMI), heart failure (HF) or cardiac surgery. While there is solid evidence for the treatment of other cardiovascular diseases of acute onset, treatment strategies in haemodynamic instability due to CS and LCOS remains less robustly supported by the given scientific literature. Therefore, we have analysed the current body of evidence for the treatment of CS or LCOS with inotropic and/or vasodilating agents. This is the second update of a Cochrane review originally published in 2014. OBJECTIVES: Assessment of efficacy and safety of cardiac care with positive inotropic agents and vasodilator agents in CS or LCOS due to AMI, HF or after cardiac surgery. SEARCH METHODS: We conducted a search in CENTRAL, MEDLINE, Embase and CPCI-S Web of Science in October 2019. We also searched four registers of ongoing trials and scanned reference lists and contacted experts in the field to obtain further information. No language restrictions were applied. SELECTION CRITERIA: Randomised controlled trials (RCTs) enrolling patients with AMI, HF or cardiac surgery complicated by CS or LCOS. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures according to Cochrane standards. MAIN RESULTS: We identified 19 eligible studies including 2385 individuals (mean or median age range 56 to 73 years) and three ongoing studies. We categorised studies into 11 comparisons, all against standard cardiac care and additional other drugs or placebo. These comparisons investigated the efficacy of levosimendan versus dobutamine, enoximone or placebo; enoximone versus dobutamine, piroximone or epinephrine-nitroglycerine; epinephrine versus norepinephrine or norepinephrine-dobutamine; dopexamine versus dopamine; milrinone versus dobutamine and dopamine-milrinone versus dopamine-dobutamine. All trials were published in peer-reviewed journals, and analyses were done by the intention-to-treat (ITT) principle. Eighteen of 19 trials were small with only a few included participants. An acknowledgement of funding by the pharmaceutical industry or missing conflict of interest statements occurred in nine of 19 trials. In general, confidence in the results of analysed studies was reduced due to relevant study limitations (risk of bias), imprecision or indirectness. Domains of concern, which showed a high risk in more than 50% of included studies, encompassed performance bias (blinding of participants and personnel) and bias affecting the quality of evidence on adverse events. All comparisons revealed uncertainty on the effect of inotropic/vasodilating drugs on all-cause mortality with a low to very low quality of evidence. In detail, the findings were: levosimendan versus dobutamine (short-term mortality: RR 0.60, 95% CI 0.36 to 1.03; participants = 1701; low-quality evidence; long-term mortality: RR 0.84, 95% CI 0.63 to 1.13; participants = 1591; low-quality evidence); levosimendan versus placebo (short-term mortality: no data available; long-term mortality: RR 0.55, 95% CI 0.16 to 1.90; participants = 55; very low-quality evidence); levosimendan versus enoximone (short-term mortality: RR 0.50, 0.22 to 1.14; participants = 32; very low-quality evidence; long-term mortality: no data available); epinephrine versus norepinephrine-dobutamine (short-term mortality: RR 1.25; 95% CI 0.41 to 3.77; participants = 30; very low-quality evidence; long-term mortality: no data available); dopexamine versus dopamine (short-term mortality: no deaths in either intervention arm; participants = 70; very low-quality evidence; long-term mortality: no data available); enoximone versus dobutamine (short-term mortality RR 0.21; 95% CI 0.01 to 4.11; participants = 27; very low-quality evidence; long-term mortality: no data available); epinephrine versus norepinephrine (short-term mortality: RR 1.81, 0.89 to 3.68; participants = 57; very low-quality evidence; long-term mortality: no data available); and dopamine-milrinone versus dopamine-dobutamine (short-term mortality: RR 1.0, 95% CI 0.34 to 2.93; participants = 20; very low-quality evidence; long-term mortality: no data available). No information regarding all-cause mortality were available for the comparisons milrinone versus dobutamine, enoximone versus piroximone and enoximone versus epinephrine-nitroglycerine. AUTHORS' CONCLUSIONS: At present, there are no convincing data supporting any specific inotropic or vasodilating therapy to reduce mortality in haemodynamically unstable patients with CS or LCOS. Considering the limited evidence derived from the present data due to a high risk of bias and imprecision, it should be emphasised that there is an unmet need for large-scale, well-designed randomised trials on this topic to close the gap between daily practice in critical care of cardiovascular patients and the available evidence. In light of the uncertainties in the field, partially due to the underlying methodological flaws in existing studies, future RCTs should be carefully designed to potentially overcome given limitations and ultimately define the role of inotropic agents and vasodilator strategies in CS and LCOS.

Polyunsaturated Fatty Acids of Both the Omega-3 and the Omega-6 Family Abrogate the Cytokine-Induced Upregulation of miR-29a-3p by Endothelial Cells.

Cellular processes fundamentally depend on protein expression control. At this, protein expression is regulated on the transcriptional and the post-transcriptional level. PUFAs are already known to affect gene transcription. The present study was conducted to answer the question whether PUFAs are also able to impact on the miRNA-mediated post-transcriptional fine-tuning of mRNA copy numbers. To this end, cellular miRNA profiles were screened by means of next-generation sequencing and NanoString analysis to compare PUFA-enriched to unsupplemented endothelial cells exposed to an inflammatory milieu. Validation took place by droplet digital PCR, allowing for an absolute quantification of RNA copy numbers. The analyses revealed that the stimulation-induced upregulation of miR-29a-3p is blocked by PUFA enrichment of endothelial cells. What is more, mRNA copy numbers of miR-29a-3p targets, namely the coagulation factors PAI-1, TF, and vWF, as well as the proinflammatory cytokines IL-1ß, IL-6, and IL-8, were reduced in PUFA-enriched endothelial cells compared to unsupplemented cells, counteracting the stimulatory effect of an inflammatory environment. These data hint toward a new mechanism of action by which PUFAs modulate the functionality of endothelial cells. Apparently, the inflammation-modulating properties of PUFAs are also mediated at the post-transcriptional level.

Lipid composition of membrane microdomains isolated detergent-free from PUFA supplemented RAW264.7 macrophages.

Profound alterations in the lipid profile of raft and non-raft plasma membrane microdomains were found when RAW264.7 macrophages were supplemented with polyunsaturated fatty acids (PUFAs) in physiologically relevant concentrations. For the first time lipids in the detergent-free isolated membrane domains of phagocytic immune cells were characterized by mass spectrometry. The extent of remodeling of the membrane lipids differed with different n3 and n6 PUFA supplements. The mildest effects were detected for α-linolenic acid (LNA) and linoleic acid (LA), the C18 precursors of the n3 and n6 families, respectively. When the effects of highly unsaturated PUFAs were compared, eicosapentaenoic acid (EPA) caused more extensive restructuring of membrane lipids than docosahexaenoic acid (DHA) or arachidonic acid (AA). The supplements altered the lipid species composition of both the raft and non-raft membrane fractions. The rafts containing elevated proportions of highly unsaturated lipid species may relocate sterically incompatible lipids and proteins originally belonging to this microdomain. Such effect was evident for sphingomyelin, which favored non-rafts instead of rafts after EPA supplementation. The current work suggests that the different functional consequences found previously when supplementing macrophages with either EPA or DHA have their origin in the different effects of these PUFAs on membrane architecture.

Nature of Lone-Pair-Surface Bonds and Their Scaling Relations.

We investigate the (surface) bonding of a class of industrially and biologically important molecules in which the chemically active orbital is a 2 p electron lone pair located on an N or O atom bound via single bonds to H or alkyl groups. This class includes water, ammonia, alcohols, ethers, and amines. Using extensive density functional theory (DFT) calculations, we discover scaling relations (correlations) among molecular binding energies of different members of this class: the bonding energetics of a single member can be used as a descriptor for other members. We investigate the bonding mechanism for a representative (H2O) and find the most important physical surface properties that dictate the strength and nature of the bonding through a combination of covalent and noncovalent electrostatic effects. We describe the importance of surface intrinsic electrostatic, geometric, and mechanical properties in determining the extent of the lone-pair-surface interactions. We study systems including ionic materials in which the surface positive and negative centers create strong local surface electric fields, which polarize the dangling lone pair and lead to a strong "electrostatically driven bond". We emphasize the importance of noncovalent electrostatic effects and discuss why a fully covalent picture, common in the current first-principles literature on surface bonding of these molecules, is not adequate to correctly describe the bonding mechanism and energy trends. By pointing out a completely different mechanism (charge transfer) as the major factor for binding N- and O-containing unsaturated (radical) adsorbates, we explain why their binding energies can be tuned independently from those of the aforementioned species, having potential implications in scaling-driven catalyst discovery.

Inotropic agents and vasodilator strategies for the treatment of cardiogenic shock or low cardiac output syndrome.

BACKGROUND: Cardiogenic shock (CS) and low cardiac output syndrome (LCOS) as complications of acute myocardial infarction (AMI), heart failure (HF) or cardiac surgery are life-threatening conditions. While there is a broad body of evidence for the treatment of people with acute coronary syndrome under stable haemodynamic conditions, the treatment strategies for people who become haemodynamically unstable or develop CS remain less clear. We have therefore summarised here the evidence on the treatment of people with CS or LCOS with different inotropic agents and vasodilative drugs. This is the first update of a Cochrane review originally published in 2014. OBJECTIVES: To assess efficacy and safety of cardiac care with positive inotropic agents and vasodilator strategies in people with CS or LCOS due to AMI, HF or cardiac surgery. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and CPCI-S Web of Science in June 2017. We also searched four registers of ongoing trials and scanned reference lists and contacted experts in the field to obtain further information. No language restrictions were applied. SELECTION CRITERIA: Randomised controlled trials in people with myocardial infarction, heart failure or cardiac surgery complicated by cardiogenic shock or LCOS. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We identified 13 eligible studies with 2001 participants (mean or median age range 58 to 73 years) and two ongoing studies. We categorised studies into eight comparisons, all against cardiac care and additional other active drugs or placebo. These comparisons investigated the efficacy of levosimendan versus dobutamine, enoximone or placebo, epinephrine versus norepinephrine-dobutamine, amrinone versus dobutamine, dopexamine versus dopamine, enoximone versus dopamine and nitric oxide versus placebo.All trials were published in peer-reviewed journals, and analysis was done by the intention-to-treat (ITT) principle. Twelve of 13 trials were small with few included participants. Acknowledgement of funding by the pharmaceutical industry or missing conflict of interest statements emerged in five of 13 trials. In general, confidence in the results of analysed studies was reduced due to serious study limitations, very serious imprecision or indirectness. Domains of concern, which show a high risk of more than 50%, include performance bias (blinding of participants and personnel) and bias affecting the quality of evidence on adverse events.Levosimendan may reduce short-term mortality compared to a therapy with dobutamine (RR 0.60, 95% CI 0.37 to 0.95; 6 studies; 1776 participants; low-quality evidence; NNT: 16 (patients with moderate risk), NNT: 5 (patients with CS)). This initial short-term survival benefit with levosimendan vs. dobutamine is not confirmed on long-term follow up. There is uncertainty (due to lack of statistical power) as to the effect of levosimendan compared to therapy with placebo (RR 0.48, 95% CI 0.12 to 1.94; 2 studies; 55 participants, very low-quality evidence) or enoximone (RR 0.50, 95% CI 0.22 to 1.14; 1 study; 32 participants, very low-quality evidence).All comparisons comparing other positive inotropic, inodilative or vasodilative drugs presented uncertainty on their effect on short-term mortality with very low-quality evidence and based on only one RCT. These single studies compared epinephrine with norepinephrine-dobutamine (RR 1.25, 95% CI 0.41 to 3.77; 30 participants), amrinone with dobutamine (RR 0.33, 95% CI 0.04 to 2.85; 30 participants), dopexamine with dopamine (no in-hospital deaths from 70 participants), enoximone with dobutamine (two deaths from 40 participants) and nitric oxide with placebo (one death from three participants). AUTHORS' CONCLUSIONS: Apart from low quality of evidence data suggesting a short-term mortality benefit of levosimendan compared with dobutamine, at present there are no robust and convincing data to support a distinct inotropic or vasodilator drug-based therapy as a superior solution to reduce mortality in haemodynamically unstable people with cardiogenic shock or LCOS.Considering the limited evidence derived from the present data due to a generally high risk of bias and imprecision, it should be emphasised that there remains a great need for large, well-designed randomised trials on this topic to close the gap between daily practice in critical care medicine and the available evidence. It seems to be useful to apply the concept of 'early goal-directed therapy' in cardiogenic shock and LCOS with early haemodynamic stabilisation within predefined timelines. Future clinical trials should therefore investigate whether such a therapeutic concept would influence survival rates much more than looking for the 'best' drug for haemodynamic support.

Septic-Induced microRNA Expression Modulations Are Linked to Angiogenesis, Vasomotion, and Hypoxia-Induced Processes.

Sepsis is an exaggerated immune reaction to an infection, which leads to organ dysfunction especially circulatory failure. This is based on cellular processes, which are regulated by post-transcriptional gene expression modulations including microRNAs (miRNAs). In order to elucidate the role miRNAs play in septic processes, monocytes and endothelial cells were grown in an inflammatory milieu. In addition, aortas from septic mice were investigated. Expression of miRNAs was analysed by both next generation sequencing (NGS) and NanoString technology, and miRNA targets were identified by in silico analysis. Clear alterations in miRNA expression profiles were found in monocytes, endothelial cells, and aortas exposed to septic conditions compared to the respective control. In silico analysis revealed several of the differentially expressed miRNAs to be involved in cellular response to hypoxia. In endothelial cells, for instance, miR-21-5p and miR-106b-5p emerged, which are known to interact with hypoxia inducible factor 1 alpha (HIF-1α), a major player in the process of angiogenesis. In line with this, in aortas expression changes were observed for miR-144-3p, which targets HIF-1α as well. Further validated target genes of differentially expressed miRNAs encompass the vascular endothelial growth factor receptor 1 (VEGFR1) and the vascular endothelial growth factor A (VEGFA), which represent essential mediators of angiogenesis. Moreover, several miRNAs impacting on genes encoding mediators of vasomotion were identified to be altered in their expression profiles in context of an inflammatory milieu. Altogether, the data indicate that miRNAs are an interesting starting point for functional and mechanistic sepsis research.

Hyperbaric Oxygen Therapy in Necrotizing Soft Tissue Infections: A Retrospective Study.

Necrotizing soft tissue infection is a severe life-threatening disease correlated with high mortality. Until now, therapeutic concepts include antimicrobial, intensive care and surgical interventions, as well as the application of hyperbaric oxygenation (HBO), which still has a controversial status. Evidence of the therapeutic concept of HBO is, so far, limited to positive experiences in case studies and physiological benefits in animal studies. That is why the HBO therapy method is not yet fully established. In this light, a retrospective data analysis was conducted. The analysis involved 91 intensive care patients in the Clinic for Anesthesiology and Surgical Intensive Care at the University Hospital Halle (Saale) who, because of a necrotizing soft tissue infection, were treated with HBO therapy (period of observation from 2008 to second quarter 2017). Treatment outcome was examined with regard to mortality, complications, time spent in the intensive care unit, and functional limitations. The criteria of therapy relevance, therapy management, and conclusions drawn from the treatment results were evaluated. By examining the result of combining all four categories of treatment, we aim to investigate established guidelines and their practicability. We expect treatment with HBO to have no disadvantages compared with acknowledged treatment concepts. This study considers the success of treatment as a result of complying with optimal therapy. In a contribution to establish coverage use and an inventory of hyperbaric chambers, we also aim to create a national case register, so that patients do not have to depend on long and risky transportations.

Polyunsaturated Fatty Acids Induce ROS Synthesis in Microvascular Endothelial Cells.

In sepsis, endothelial dysfunction is a crucial driver known to limit the survival rate of affected patients. For this, ROS-mediated signaling plays an important role in endothelial communication and functionality. In the management of sepsis, polyunsaturated fatty acids (PUFA) have received increasing attention regarding their anti-inflammatory potential neglecting the oxidative properties of these substances. Therefore, in the present study we examined the capacity of PUFA to interfere with the expression of major ROS-producing enzymes, as well as endothelial ROS production itself. The human microvascular endothelial cells TIME (ATCC number: CRL-4025) were used. Cells were cultured in medium enriched with LNA (C18:3n3), EPA (C20:5n3), DHA (C22:6n3), LA (C18:2n6), or AA (C20:4n6) in concentrations of 15 µM totaling 144 h. Stimulation of cells was performed in the last 24 h of fatty acid supplementation by addition of the cytokines TNF-α + IL-1ß + IFN-γ (5 ng/ml each). Gene expression of eNOS, COX-2, and NOX-4 was evaluated by qPCR. ROS synthesis was analyzed by means of a flow cytometry-based rhodamine 123 assay. Cytokine stimulation was found to differentially affect gene expression of major ROS synthesizing enzymes: eNOS was decreased whereas COX-2 and NOX-4 were increased. As a consequence, cytokine stimulation had no effect on rhodamine accumulation in endothelial cells. PUFA supplementation alone did not affect the gene expression of eNOS, COX-2, and NOX-4. Nevertheless, an increasing action of PUFA on the stimulation-induced reduction in eNOS expression was found. More importantly, the number of rhodamine positive endothelial cells almost doubled following enrichment with the PUFA EPA, DHA or AA. This effect was independent of the stimulation status of the cells but seemed to be related to the number of double bonds of a supplemented fatty acid. Our data warrant further studies to ensure that increased endothelial cell oxidative stress is not boosted by PUFA in septic patients.

TCAIM decreases T cell priming capacity of dendritic cells by inhibiting TLR-induced Ca2+ influx and IL-2 production.

We previously showed that the T cell activation inhibitor, mitochondrial (Tcaim) is highly expressed in grafts of tolerance-developing transplant recipients and that the encoded protein is localized within mitochondria. In this study, we show that CD11c(+) dendritic cells (DCs), as main producers of TCAIM, downregulate Tcaim expression after LPS stimulation or in vivo alloantigen challenge. LPS-stimulated TCAIM-overexpressing bone marrow-derived DC (BMDCs) have a reduced capacity to induce proliferation of and cytokine expression by cocultured allogeneic T cells; this is not due to diminished upregulation of MHC or costimulatory molecules. Transcriptional profiling also revealed normal LPS-mediated upregulation of the majority of genes involved in TLR signaling. However, TCAIM BMDCs did not induce Il2 mRNA expression upon LPS stimulation in comparison with Control-BMDCs. In addition, TCAIM overexpression abolished LPS-mediated Ca(2+) influx and mitochondrial reactive oxygen species formation. Addition of IL-2 to BMDC-T cell cocultures restored the priming capacity of TCAIM BMDCs for cocultured allogeneic CD8(+) T cells. Furthermore, BMDCs of IL-2-deficient mice showed similarly abolished LPS-induced T cell priming as TCAIM-overexpressing wild type BMDCs. Thus, TCAIM interferes with TLR4 signaling in BMDCs and subsequently impairs their T cell priming capacity, which supports its role for tolerance induction.

Impact of Polyunsaturated Fatty Acids on miRNA Profiles of Monocytes/Macrophages and Endothelial Cells-A Pilot Study.

Alteration of miRNAs and dietary polyunsaturated fatty acids (PUFAs) underlies vascular inflammation. PUFAs are known to be incorporated into the cell membrane of monocytes/macrophages or endothelial cells, the major cellular players of vascular diseases, thereby affecting cellular signal transduction. Nevertheless, there are no investigations concerning the PUFA impact on miRNA expression by these cells. With regard to the key role miRNAs play for overall cellular functionality, this study aims to elucidate whether PUFAs affect miRNA expression profiles. To this end, the monocyte/macrophage cell line RAW264.7 and the endothelial cell line TIME were enriched with either docosahexaenoic acid (DHA; n3-PUFA) or arachidonic acid (AA; n6-PUFA) until reaching a stable incorporation into the plasma membrane and, at least in part, exposed to an inflammatory milieu. Expressed miRNAs were determined by deep sequencing, and compared to unsupplemented/unstimulated controls. Data gained clearly show that PUFAs in fact modulate miRNA expression of both cell types analyzed regardless the presence/absence of an inflammatory stimulator. Moreover, certain miRNAs already linked to vascular inflammation were found to be affected by cellular PUFA enrichment. Hence, vascular inflammation appears to be influenced by dietary fatty acids, inter alia, via PUFA-mediated modulation of the type and amount of miRNAs synthesized by cells involved in the inflammatory process.

Impact of Unsaturated Fatty Acids on Cytokine-Driven Endothelial Cell Dysfunction.

Polyunsaturated fatty acids (PUFA) are reported to exert prophylactic and acute therapeutic effects in diseases linked to endothelial dysfunction. In the present study, the consequences of a PUFA enrichment of endothelial cells (cell line TIME) on cell viability, expression of the cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte-macrophage colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein 1 (MCP-1), synthesis of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and vascular adhesion molecule 1 (VCAM-1), and production of the coagulation factors plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), and tissue factor (TF) was analyzed in parallel. PUFA of both the n3 and the n6 family were investigated in a physiologically relevant concentration of 15 µM, and experiments were performed in both the presence and the absence of the pro-inflammatory cytokines interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Supplementation of the culture medium with particular fatty acids was found to have a promoting effect on cellular production of the cytokines IL-6, IL-8, GM-CSF, and MCP-1. Further on, PUFA treatment in the absence of a stimulant diminished the percentage of endothelial cells positive for ICAM-1, and adversely affected the stimulation-induced upregulation of VCAM-1. Cell viability and production of coagulation factors were not or only marginally affected by supplemented fatty acids. Altogether, the data indicate that PUFA of either family are only partially able to counterbalance the destructive consequences of an endothelial dysfunction.

Formation of a ZnO overlayer in industrial Cu/ZnO/Al2 O3 catalysts induced by strong metal-support interactions.

In industrially relevant Cu/ZnO/Al2 O3 catalysts for methanol synthesis, the strong metal support interaction between Cu and ZnO is known to play a key role. Here we report a detailed chemical transmission electron microscopy study on the nanostructural consequences of the strong metal support interaction in an activated high-performance catalyst. For the first time, clear evidence for the formation of metastable "graphite-like" ZnO layers during reductive activation is provided. The description of this metastable layer might contribute to the understanding of synergistic effects between the components of the Cu/ZnO/Al2 O3 catalysts.

Prevention of graft-versus-host disease by adoptive T regulatory therapy is associated with active repression of peripheral blood Toll-like receptor 5 mRNA expression.

Acute graft-versus-host disease (GVHD) occurs in 40% to 60% of recipients of partially matched umbilical cord blood transplantation (UCBT). In a phase I study, adoptive transfer of expanded CD4(+)CD25(+)Foxp3(+) natural regulatory T cells (nTregs) resulted in a reduced incidence of grade II-IV acute GVHD. To investigate potential mechanisms responsible for the reduced GVHD risk, we analyzed peripheral blood mononuclear cell mRNA expression of a tolerance gene set previously identified in operation- tolerant kidney transplant recipients, comparing healthy controls and patients who received nTregs and those who did not receive nTregs with and without experiencing GVHD. Samples from patients receiving nTregs regardless of GVHD status showed increased expression of Foxp3 expression, as well as B cell-related tolerance marker. This was correlated with early B cell recovery, predominately of naïve B cells, and nearly normal T cell reconstitution. CD8(+) T cells showed reduced signs of activation (HLA-DR(+) expression) compared with conventionally treated patients developing GVHD. In contrast, patients with GVHD had significantly increased TLR5 mRNA expression, whereas nTreg-treated patients without GVHD had reduced TLR5 mRNA expression. We identified Lin(-)HLADR(-)CD33(+)CD16(+) cells and CD14(++)CD16(-) monocytes as the main TLR5 producers, especially in samples of conventionally treated patients developing GVHD. Taken together, these data reveal interesting similarities and differences between tolerant organ and nTreg-treated hematopoietic stem cell transplantation recipients.

Generation of highly effective and stable murine alloreactive Treg cells by combined anti-CD4 mAb, TGF-ß, and RA treatment.

The transfer of alloreactive regulatory T (aTreg) cells into transplant recipients represents an attractive treatment option to improve long-term graft acceptance. We recently described a protocol for the generation of aTreg cells in mice using a nondepleting anti-CD4 antibody (aCD4). Here, we investigated whether adding TGF-ß and retinoic acid (RA) or rapamycin (Rapa) can further improve aTreg-cell generation and function. Murine CD4(+) T cells were cultured with allogeneic B cells in the presence of aCD4 alone, aCD4+TGF-ß+RA or aCD4+Rapa. Addition of TGF-ß+RA or Rapa resulted in an increase of CD25(+)Foxp3(+)-expressing T cells. Expression of CD40L and production of IFN-γ and IL-17 was abolished in aCD4+TGF-ß+RA aTreg cells. Additionally, aCD4+TGF-ß+RA aTreg cells showed the highest level of Helios and Neuropilin-1 co-expression. Although CD25(+)Foxp3(+) cells from all culture conditions displayed complete demethylation of the Treg-specific demethylated region, aCD4+TGF-ß+RA Treg cells showed the most stable Foxp3 expression upon restimulation. Consequently, aCD4+TGF-ß+RA aTreg cells suppressed effector T-cell differentiation more effectively in comparison to aTreg cells harvested from all other cultures, and furthermore inhibited acute graft versus host disease and especially skin transplant rejection. Thus, addition of TGF-ß+RA seems to be superior over Rapa in stabilising the phenotype and functional capacity of aTreg cells.