The Western diet is rich in salt, and a high salt diet (HSD) is suspected to be a risk factor for cardiovascular diseases. It is now widely accepted that an experimental HSD can stimulate components ...of the immune system, potentially exacerbating certain autoimmune diseases, or alternatively, improving defenses against certain infections, such as cutaneous leishmaniasis. However, recent findings show that an experimental HSD may also aggravate other infections (e.g., pyelonephritis or systemic listeriosis). Here, we discuss the modulatory effects of a HSD on the microbiota, metabolic signaling, hormonal responses, local sodium concentrations, and their effects on various immune cell types in different tissues. We describe how these factors are integrated, resulting either in immune stimulation or suppression in various tissues and disease settings.
A HSD can stimulate local tissue-specific accumulation of sodium in mice and humans.Increases in sodium concentration can amplify inflammatory macrophage and T cell responses in mice and humans.A HSD can affect systemic immune responses by altering the intestinal microbiome and its immunomodulatory metabolites in mice and humans.A HSD can systemically suppress neutrophil-mediated immune responses by causing hyperglucorticoidism without diurnal rhythm in mice and humans.The effect of a HSD on immunity is dependent on the tissue/organ affected, the type of immune cells implicated, and the presence and type of disease.
Utilizing data from a survey of attitudes and behavior of more than 2, 500 residents of selected rural, urban, and university communities in the Federal Republic of Germany, Edward Muller attempts to ...formulate and to test a general multivariate theory about what motivates individuals to participate in aggressive political action. Since this kind of political behavior is infrequent in addition to being difficult to measure, it rarely has been subjected to rigorous scientific investigation at the micro-level. Professor Muller's study is an attempt to understand the causes of aggressive political participation using quantitative techniques.Originally published in 1979.The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
This paper argues for efficient environmental regulations that equate the marginal damage of pollution to marginal abatement costs across space. The paper estimates the source-specific marginal ...damages of air pollution and calculates the welfare gain from making the current sulfur dioxide allowance trading program for power plants more efficient. The savings from using trading ratios based on marginal damages are between $310 and $940 million per year. The potential savings from setting aggregate emissions efficiently and from including more sources of air pollution are many times higher.
Observations of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) provide valuable comparative data for understanding the significance of conspecific killing. Two kinds of hypothesis have been ...proposed. Lethal violence is sometimes concluded to be the result of adaptive strategies, such that killers ultimately gain fitness benefits by increasing their access to resources such as food or mates. Alternatively, it could be a non-adaptive result of human impacts, such as habitat change or food provisioning. To discriminate between these hypotheses we compiled information from 18 chimpanzee communities and 4 bonobo communities studied over five decades. Our data include 152 killings (n = 58 observed, 41 inferred, and 53 suspected killings) by chimpanzees in 15 communities and one suspected killing by bonobos. We found that males were the most frequent attackers (92% of participants) and victims (73%); most killings (66%) involved intercommunity attacks; and attackers greatly outnumbered their victims (median 8:1 ratio). Variation in killing rates was unrelated to measures of human impacts. Our results are compatible with previously proposed adaptive explanations for killing by chimpanzees, whereas the human impact hypothesis is not supported.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Methods of synthesizing, stabilizing and vectorizing magnetic iron nanoparticles are discussed. Substantial progress in creating such nanoparticles in a wide variety of compositions and sizes has ...been made.
The maize smut fungus Ustilago maydis is a model organism for elucidating host colonization strategies of biotrophic fungi. Here, we performed an in depth transcriptional profiling of the entire ...plant-associated development of U. maydis wild-type strains. In our analysis, we focused on fungal metabolism, nutritional strategies, secreted effectors, and regulatory networks. Secreted proteins were enriched in three distinct expression modules corresponding to stages on the plant surface, establishment of biotrophy, and induction of tumors. These modules are likely the key determinants for U. maydis virulence. With respect to nutrient utilization, we observed that expression of several nutrient transporters was tied to these virulence modules rather than being controlled by nutrient availability. We show that oligopeptide transporters likely involved in nitrogen assimilation are important virulence factors. By measuring the intramodular connectivity of transcription factors, we identified the potential drivers for the virulence modules. While known components of the b-mating type cascade emerged as inducers for the plant surface and biotrophy module, we identified a set of yet uncharacterized transcription factors as likely responsible for expression of the tumor module. We demonstrate a crucial role for leaf tumor formation and effector gene expression for one of these transcription factors.
Abstract
Aims
Atherosclerotic cardiovascular disease (ACVD) is a major cause of mortality and morbidity worldwide, and increased low-density lipoproteins (LDLs) play a critical role in development ...and progression of atherosclerosis. Here, we examined for the first time gut immunomodulatory effects of the microbiota-derived metabolite propionic acid (PA) on intestinal cholesterol metabolism.
Methods and results
Using both human and animal model studies, we demonstrate that treatment with PA reduces blood total and LDL cholesterol levels. In apolipoprotein E−/− (Apoe−/−) mice fed a high-fat diet (HFD), PA reduced intestinal cholesterol absorption and aortic atherosclerotic lesion area. Further, PA increased regulatory T-cell numbers and interleukin (IL)-10 levels in the intestinal microenvironment, which in turn suppressed the expression of Niemann-Pick C1-like 1 (Npc1l1), a major intestinal cholesterol transporter. Blockade of IL-10 receptor signalling attenuated the PA-related reduction in total and LDL cholesterol and augmented atherosclerotic lesion severity in the HFD-fed Apoe−/− mice. To translate these preclinical findings to humans, we conducted a randomized, double-blinded, placebo-controlled human study (clinical trial no. NCT03590496). Oral supplementation with 500 mg of PA twice daily over the course of 8 weeks significantly reduced LDL −15.9 mg/dL (−8.1%) vs. −1.6 mg/dL (−0.5%), P = 0.016, total −19.6 mg/dL (−7.3%) vs. −5.3 mg/dL (−1.7%), P = 0.014 and non-high-density lipoprotein cholesterol levels PA vs. placebo: −18.9 mg/dL (−9.1%) vs. −0.6 mg/dL (−0.5%), P = 0.002 in subjects with elevated baseline LDL cholesterol levels.
Conclusion
Our findings reveal a novel immune-mediated pathway linking the gut microbiota-derived metabolite PA with intestinal Npc1l1 expression and cholesterol homeostasis. The results highlight the gut immune system as a potential therapeutic target to control dyslipidaemia that may introduce a new avenue for prevention of ACVDs.
Graphical Abstract
Graphical Abstract
The figure illustrates the proposed model of the cholesterol-lowering and atheroprotective properties of propionate. A high-fat high-cholesterol diet causes a disbalance of immune cells in the small intestinal microenvironment, with reduced regulatory T cell frequencies and interleukin-10 concentrations. Altered regulatory T cell levels are rescued upon exogenous propionate supplementation, with increased local levels. This in turn modulates NPC1L1 expression and membrane density, with a subsequent reduction in cholesterol absorption, ultimately leading to reduced atherogenesis. The illustration was adopted from Servier Medical Art (http://smart.servier.com/), licensed under a Creative Common Attribution 3.0 Generic License. HFD, high-fat diet; IL-10, interleukin-10; NPC1L1, Niemann-Pick C1-like 1; PA, propionic acid; Treg, regulatory T cell.
The effects of feeding an 80% plant protein diet, with and without fish protein hydrolysate (FPH) supplementation, on the growth and gut health of Atlantic salmon were investigated. Fish were fed ...either (A) a control diet containing 35% fishmeal, (B) an 80% plant protein diet with 15% fishmeal, (C) an 80% plant protein diet with 5% fishmeal and 10% partly hydrolysed protein, or (D) an 80% plant protein diet with 5% fishmeal and 10% soluble protein hydrolysate. Fish on the 80% plant- 15% fishmeal diet were significantly smaller than fish in the other dietary groups. However, partly-hydrolysed protein supplementation allowed fish to grow as well as fish fed the control 35% fishmeal diet. Fish fed the FPH diets (diets C and D) had significantly higher levels of amino acids in their blood, including 48% and 27% more branched chain amino acids compared to fish on the 35% fishmeal diet, respectively. Plant protein significantly altered gut microbial composition, significantly decreasing α-diversity. Spirochaetes and the families Moritellaceae, Psychromonadaceae, Helicobacteraceae and Bacteroidaceae were all found at significantly lower abundances in the groups fed 80% plant protein diets compared to the control fishmeal diet.
Cytochrome P450 (CYP)-dependent metabolites of arachidonic acid (AA) contribute to the regulation of cardiovascular function. CYP enzymes also accept EPA and DHA to yield more potent vasodilatory and ...potentially anti-arrhythmic metabolites, suggesting that the endogenous CYP-eicosanoid profile can be favorably shifted by dietary omega-3 fatty acids. To test this hypothesis, 20 healthy volunteers were treated with an EPA/DHA supplement and analyzed for concomitant changes in the circulatory and urinary levels of AA-, EPA-, and DHA-derived metabolites produced by the cyclooxygenase-, lipoxygenase (LOX)-, and CYP-dependent pathways. Raising the Omega-3 Index from about four to eight primarily resulted in a large increase of EPA-derived CYP-dependent epoxy-metabolites followed by increases of EPA- and DHA-derived LOX-dependent monohydroxy-metabolites including the precursors of the resolvin E and D families; resolvins themselves were not detected. The metabolite/precursor fatty acid ratios indicated that CYP epoxygenases metabolized EPA with an 8.6-fold higher efficiency and DHA with a 2.2-fold higher efficiency than AA. Effects on leukotriene, prostaglandin E, prostacyclin, and thromboxane formation remained rather weak. We propose that CYP-dependent epoxy-metabolites of EPA and DHA may function as mediators of the vasodilatory and cardioprotective effects of omega-3 fatty acids and could serve as biomarkers in clinical studies investigating the cardiovascular effects of EPA/DHA supplementation.
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