Inhibition of indoleamine 2,3-dioxygenase in mixed lymphocyte reaction affects glucose influx and enzymes involved in aerobic glycolysis and glutaminolysis in alloreactive T-cells

Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immunity. T-cell proliferation and differentiation to effector cells require increased glucose consumption, aerobic glycolysis and glutaminolysis. The effect of IDO on the above metabolic pathways was evaluated in alloreactive T-cells. Mixed lymphocyte reaction (MLR) in the presence or not of the IDO inhibitor, 1-DL-methyl-tryptophane (1-MT), was used. In MLRs, 1-MT decreased tryptophan consumption, increased cell proliferation, glucose influx and lactate production, whereas it decreased tricarboxylic acid cycle activity. In T-cells, from the two pathways that could sense tryptophan depletion, i.e. general control nonrepressed 2 (GCN2) kinase and mammalian target of rapamycin complex 1, 1-MT reduced only the activity of the GCN2 kinase. Additionally 1-MT treatment of MLRs altered the expression and/or the phosphorylation state of glucose transporter-1 and of key enzymes involved in glucose metabolism and glutaminolysis in alloreactive T-cells in a way that favors glucose influx, aerobic glycolysis and glutaminolysis. Thus in alloreactive T-cells, IDO through activation of the GCN2 kinase, decreases glucose influx and alters key enzymes involved in metabolism, decreasing aerobic glycolysis and glutaminolysis. Acting in such a way, IDO could be considered as a constraining factor for alloreactive T-cell proliferation and differentiation to effector T-cell subtypes.

Climate extremes and the carbon cycle

The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget.

Caffeine affects the biological responses of human hematopoietic cells of myeloid lineage via downregulation of the mTOR pathway and xanthine oxidase activity.

Correction of human myeloid cell function is crucial for the prevention of inflammatory and allergic reactions as well as leukaemia progression. Caffeine, a naturally occurring food component, is known to display anti-inflammatory effects which have previously been ascribed largely to its inhibitory actions on phosphodiesterase. However, more recent studies suggest an additional role in affecting the activity of the mammalian target of rapamycin (mTOR), a master regulator of myeloid cell translational pathways, although detailed molecular events underlying its mode of action have not been elucidated. Here, we report the cellular uptake of caffeine, without metabolisation, by healthy and malignant hematopoietic myeloid cells including monocytes, basophils and primary acute myeloid leukaemia mononuclear blasts. Unmodified caffeine downregulated mTOR signalling, which affected glycolysis and the release of pro-inflammatory/pro-angiogenic cytokines as well as other inflammatory mediators. In monocytes, the effects of caffeine were potentiated by its ability to inhibit xanthine oxidase, an enzyme which plays a central role in human purine catabolism by generating uric acid. In basophils, caffeine also increased intracellular cyclic adenosine monophosphate (cAMP) levels which further enhanced its inhibitory action on mTOR. These results demonstrate an important mode of pharmacological action of caffeine with potentially wide-ranging therapeutic impact for treating non-infectious disorders of the human immune system, where it could be applied directly to inflammatory cells.

Results of the randomized, placebo-controlled clopidogrel and acetylsalicylic acid in bypass surgery for peripheral arterial disease (CASPAR) trial

OBJECTIVE: Dual antiplatelet therapy with clopidogrel plus acetylsalicylic acid (ASA) is superior to ASA alone in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention. We sought to determine whether clopidogrel plus ASA conferred benefit on limb outcomes over ASA alone in patients undergoing below-knee bypass grafting. METHODS: Patients undergoing unilateral, below-knee bypass graft for atherosclerotic peripheral arterial disease (PAD) were enrolled 2 to 4 days after surgery and were randomly assigned to clopidogrel 75 mg/day plus ASA 75 to 100 mg/day or placebo plus ASA 75 to 100 mg/day for 6 to 24 months. The primary efficacy endpoint was a composite of index-graft occlusion or revascularization, above-ankle amputation of the affected limb, or death. The primary safety endpoint was severe bleeding (Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries [GUSTO] classification). RESULTS: In the overall population, the primary endpoint occurred in 149 of 425 patients in the clopidogrel group vs 151 of 426 patients in the placebo (plus ASA) group (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.78-1.23). In a prespecified subgroup analysis, the primary endpoint was significantly reduced by clopidogrel in prosthetic graft patients (HR, 0.65; 95% CI, 0.45-0.95; P = .025) but not in venous graft patients (HR, 1.25; 95% CI, 0.94-1.67, not significant [NS]). A significant statistical interaction between treatment effect and graft type was observed (P(interaction) = .008). Although total bleeds were more frequent with clopidogrel, there was no significant difference between the rates of severe bleeding in the clopidogrel and placebo (plus ASA) groups (2.1% vs 1.2%). CONCLUSION: The combination of clopidogrel plus ASA did not improve limb or systemic outcomes in the overall population of PAD patients requiring below-knee bypass grafting. Subgroup analysis suggests that clopidogrel plus ASA confers benefit in patients receiving prosthetic grafts without significantly increasing major bleeding risk.

Metabolic pathway and distribution of superparamagnetic iron oxide nanoparticles: in vivo study

Experimental tissue fusion benefits from the selective heating of superparamagnetic iron oxide nanoparticles (SPIONs) under high frequency irradiation. However, the metabolic pathways of SPIONs for tissue fusion remain unknown. Hence, the goal of this in vivo study was to analyze the distribution of SPIONs in different organs by means of magnetic resonance imaging (MRI) and histological analysis after a SPION-containing patch implantation.

Parallel synthesis and nucleic acid binding properties of C(6')-[alpha]-functionalized bicyclo-DNA

Two novel bicyclo-T nucleosides carrying a hydroxyl or a carboxymethyl substituent in C(6')-[alpha]-position were prepared and incorporated into oligodeoxynucleotides. During oligonucleotide deprotection the carboxymethyl substituent was converted into different amide substituents in a parallel way. Tm-measurements showed no dramatic differences in both, thermal affinity and mismatch discrimination, compared to unmodified oligonucleotides. The post-synthetic modification of the carboxymethyl substituent allows in principle for a parallel preparation of a library of oligonucleotides carrying diverse substituents at C(6'). In addition, functional groups can be placed into unique positions in a DNA double helix.

miR-34a and miR-15a/16 are co-regulated in non-small cell lung cancer and control cell cycle progression in a synergistic and Rb-dependent manner

microRNAs (miRNAs) are small non-coding RNAs that are frequently involved in carcinogenesis. Although many miRNAs form part of integrated networks, little information is available how they interact with each other to control cellular processes. miR-34a and miR-15a/16 are functionally related; they share common targets and control similar processes including G1-S cell cycle progression and apoptosis. The aim of this study was to investigate the combined action of miR-34a and miR-15a/16 in non-small cell lung cancer (NSCLC) cells.

MicroRNA-29b is involved in the Src-ID1 signaling pathway and is dysregulated in human lung adenocarcinoma

The c-Src kinase regulates cancer cell invasion through inhibitor of DNA binding/differentiation 1 (ID1). Src and ID1 are frequently overexpressed in human lung adenocarcinoma. The current study aimed at identifying microRNAs (miRNAs) involved in the Src-ID1 signaling in lung cancer. Incubation of lung cancer cells with the Src inhibitor saracatinib led to the upregulation of several miRNAs including miR-29b, which was the most highly upregulated miRNA with predicted binding to the ID1 3'-untranslated region (UTR). Luciferase reporter assays confirmed direct binding of miR-29b to the ID1 3'-UTR. Expression of miR-29b suppressed ID1 levels and significantly reduced migration and invasion. Expression of antisense-miR-29b (anti-miR-29b), on the other hand, enhanced ID1 mRNA and protein levels, and significantly increased lung cancer cell migration and invasion, a hallmark of the Src-ID1 pathway. The ectopic expression of ID1 in miR-29b-overexpressing cells was able to rescue the migratory potential of these cells. Both, anti-miR-29b and ID1 overexpression diminished the effects of the Src inhibitors saracatinib and dasatinib on migration and invasion. Saracatinib and dasatinib decreased c-Myc transcriptional repression on miR-29b and led to increased ID1 protein levels, whereas forced expression of c-Myc repressed miR-29b and induced ID1. In agreement, we showed direct recruitment of c-Myc to the miR-29b promoter. miR-29b was significantly downregulated in primary lung adenocarcinoma samples compared with matched alveolar lung tissue, and miR-29b expression was a significant prognostic factor for patient outcome. These results suggest that miR-29b is involved in the Src-ID1 signaling pathway, is dysregulated in lung adenocarcinoma and is a potential predictive marker for Src kinase inhibitors.

UPLC-MS-based urine metabolomics reveals indole-3-lactic acid and phenyllactic acid as conserved biomarkers for alcohol-induced liver disease in the Ppara-null mouse model

Since the development and prognosis of alcohol-induced liver disease (ALD) vary significantly with genetic background, identification of a genetic background-independent noninvasive ALD biomarker would significantly improve screening and diagnosis. This study explored the effect of genetic background on the ALD-associated urinary metabolome using the Ppara-null mouse model on two different backgrounds, C57BL/6 (B6) and 129/SvJ (129S), along with their wild-type counterparts. Reversed-phase gradient UPLC-ESI-QTOF-MS analysis revealed that urinary excretion of a number of metabolites, such as ethylsulfate, 4-hydroxyphenylacetic acid, 4-hydroxyphenylacetic acid sulfate, adipic acid, pimelic acid, xanthurenic acid, and taurine, were background-dependent. Elevation of ethyl-β-d-glucuronide and N-acetylglycine was found to be a common signature of the metabolomic response to alcohol exposure in wild-type as well as in Ppara-null mice of both strains. However, increased excretion of indole-3-lactic acid and phenyllactic acid was found to be a conserved feature exclusively associated with the alcohol-treated Ppara-null mouse on both backgrounds that develop liver pathologies similar to the early stages of human ALD. These markers reflected the biochemical events associated with early stages of ALD pathogenesis. The results suggest that indole-3-lactic acid and phenyllactic acid are potential candidates for conserved and pathology-specific high-throughput noninvasive biomarkers for early stages of ALD.

Self-etch primers and conventional acid-etch technique for orthodontic bonding: a systematic review and meta-analysis

The use of self-etch primers has increased steadily because of their time savings and greater simplicity; however, overall benefits and potential disadvantages and harms have not been assessed systematically. In this study, we reviewed randomized controlled trials to assess the risk of attachment failure, bonding time, and demineralization adjacent to attachments between 1-stage (self-etch) and 2-stage (acid etch) bonding in orthodontic patients over a minimum follow-up period of 12 months.

Lipopolysaccharide and lipoteichoic acid induce different immune responses in the bovine mammary gland

Different pathogens, such as Escherichia coli and Staphylococcus aureus, can be responsible for different outcomes of mastitis; that is, acute and severe or chronic and subclinical. These differences in the disease could be related to different mammary responses to the pathogens. The objective of this study was to determine if intramammary challenge with the endotoxins lipopolysaccharide (LPS), from E. coli, and lipoteichoic acid (LTA), from Staph. aureus, induce different immune responses in vivo in milk cells and mammary tissue. To provide a reference level for comparing the challenge and to show the different stimulation of the mammary immune system on a quantitatively similar level, dosages of LPS and LTA were chosen that induced an increase of somatic cells in milk to similar maxima. One udder quarter in each of 21 lactating dairy cows was challenged with 0.2 mug of LPS or 20 mug of LTA. From these quarters and from respective control quarters, milk cells or tissue biopsies were obtained at 0, 6, and 12h relative to the challenge to measure mRNA expression of tumor necrosis factor-alpha (TNFalpha), IL-1beta, IL-8, lactoferrin, and RANTES (regulated upon activation, normal T-cell expressed and secreted). Furthermore, if no biopsies were performed, hourly milk samples were taken for measurement of somatic cell count, lactate dehydrogenase (LDH), and TNFalpha. Somatic cell count increased in all treatments to similar maxima with LPS and LTA treatments. Concentrations of TNFalpha in milk increased with LPS but not with LTA. The activity of LDH in milk increased in both treatments and was more pronounced with LPS than with LTA. The mRNA expression of TNFalpha, IL-1beta, IL-8, and RANTES showed increases in milk cells, and LPS was a stronger inducer than LTA. Lactoferrin mRNA expression decreased in milk cells with LPS and LTA treatments. The measured factors did not change in either treatment in mammary tissue. Challenge of udder quarters with dosages of LPS and LTA that induce similar increases in SCC stimulate the appearance of different immune factor patterns. This dissimilar response to LPS and LTA may partly explain the different course and intensity of mastitis after infection with E. coli and Staph. aureus, respectively.

Fracture risk and zoledronic acid therapy in men with osteoporosis

Fractures in men are a major health issue, and data on the antifracture efficacy of therapies for osteoporosis in men are limited. We studied the effect of zoledronic acid on fracture risk among men with osteoporosis.