Intestinal-epithelial LSD1 controls goblet cell maturation and effector responses required for gut immunity to bacterial and helminth infection

Infectious and inflammatory diseases in the intestine remain a serious threat for patients world-wide. Reprogramming of the intestinal epithelium towards a protective effector state is important to manage inflammation and immunity and can be therapeutically targeted. The role of epigenetic regulatory enzymes within these processes is not yet defined. Here, we use a mouse model that has an intestinal-epithelial specific deletion of the histone demethylase Lsd1 (cKO mice), which maintains the epithelium in a fixed reparative state. Challenge of cKO mice with bacteria-induced colitis or a helminth infection model both resulted in increased pathogenesis. Mechanistically, we discovered that LSD1 is important for goblet cell maturation and goblet-cell effector molecules such as RELMß. We propose that this may be in part mediated by directly controlling genes that facilitate cytoskeletal organization, which is important in goblet cell biology. This study therefore identifies intestinal-epithelial epigenetic regulation by LSD1 as a critical element in host protection from infection.     

A novel spirocyclic tropanyl-Δ2-isoxazoline derivative enhances citalopram and paroxetine binding to serotonin transporters as well as serotonin uptake

A group of spirocyclic tropanyl-Δ²-isoxazolines was synthesized exploiting the 1,3-dipolar cycloaddition of nitrile oxides to olefins. Their interaction with the dopamine and serotonin transporters (DAT and SERT, respectively) was evaluated through binding experiments. The majority of the compounds had no inhibitory effects (IC₅₀ >> 10 μM), while some had an IC₅₀ value in the range 5–10 μM (8a–c, 10b and 11c on DAT, 12b on SERT). Unexpectedly, one of the tertiary amines under investigation, that is 3′-methoxy-8-methyl-spiro{8-azabicyclo[3.2.1]octane-3,5′(4′H)-isoxazole 7a, was able to enhance at a concentration of 10 μM both [³H]citalopram and [³H]paroxetine binding to SERT in rat brain homogenate (up to 25%, due to an increase of B_max) and [³H]serotonin uptake (up to 30%) in cortical synaptosomes. This peculiar pharmacological profile of 7a suggests it binds to an allosteric site on SERT, and positions derivative 7a as a very useful tool to investigate SERT machinery.     

Antagonism of the Prokineticin System Prevents and Reverses Allodynia and Inflammation in a Mouse Model of Diabetes

Neuropathic pain is a severe diabetes complication and its treatment is not satisfactory. It is associated with neuroinflammation-related events that participate in pain generation and chronicization. Prokineticins are a new family of chemokines that has emerged as critical players in immune system, inflammation and pain. We investigated the role of prokineticins and their receptors as modulators of neuropathic pain and inflammatory responses in experimental diabetes. In streptozotocin-induced-diabetes in mice, the time course expression of prokineticin and its receptors was evaluated in spinal cord and sciatic nerves, and correlated with mechanical allodynia. Spinal cord and sciatic nerve pro- and anti-inflammatory cytokines were measured as protein and mRNA, and spinal cord GluR subunits expression studied. The effect of preventive and therapeutic treatment with the prokineticin receptor antagonist PC1 on behavioural and biochemical parameters was evaluated. Peripheral immune activation was assessed measuring macrophage and T-helper cytokine production. An up-regulation of the Prokineticin system was present in spinal cord and nerves of diabetic mice, and correlated with allodynia. Therapeutic PC1 reversed allodynia while preventive treatment blocked its development. PC1 normalized prokineticin levels and prevented the up-regulation of GluN2B subunits in the spinal cord. The antagonist restored the pro-/anti-inflammatory cytokine balance altered in spinal cord and nerves and also reduced peripheral immune system activation in diabetic mice, decreasing macrophage proinflammatory cytokines and the T-helper 1 phenotype. The prokineticin system contributes to altered sensitivity in diabetic neuropathy and its inhibition blocked both allodynia and inflammatory events underlying disease.     

Differential expression of two types of sucrose synthase-encoding genes in wheat in response to anaerobiosis, cold shock and light

The expression of two types of sucrose synthase-encoding genes, Ss1 and Ss2, in hexaploid wheat (Triticum aestivum, L.), has been investigated using type-specific probes, corresponding to the 250-270 bp C-terminal portions of the respective cDNA clones. Both types of genes are highly expressed in developing endosperm, where the expression of the Ss2 type slightly precedes in time that of the Ss1 type. Expression of Ss genes is lower in etiolated leaves and in roots than in endosperm. In the first two tissues, the Ss1 mRNA is much more abundant than the Ss2 mRNA, and the Ss1 mRNA level sharply increases in response to anaerobiosis and to cold shock (6 degrees C), while the level of Ss2 mRNA is not significantly affected. Upon illumination of etiolated leaves, the Ss1 level mRNA decreases significantly and the Ss2 mRNA level increases.     

Genotoxicity assessment of Copaiba oil and its fractions in Swiss mice

Copaiba oil-resin, extracted from the trunk of Copaifera, and traditionally used in folk medicine in the treatment of various disorders, has been shown to be an effective antiinflamatory, antitumor, antitetanus, antiseptic and anti-blenorrhagea agent. As, there are few studies evaluating its genotoxicity, this aspect of the commercial oil-resin, and its volatile and resinous fractions, were evaluated in mice by comet assay and micronucleus (MN) test. A single dose of oil resin, volatile or resin fractions (500; 1,000 or 2,000 mg/kg b.w.) was administered by gavage. The chemical compositions of Copaiba oil resin and its fractions was analyzed by gas chromatography. According to comet assaying, treatment with either one did not increase DNA damage, and as to MN testing, there was no alteration in the incidence of micronucleated polychromatic erythrocytes. Chromatographic analysis of the oil-resin itself revealed sesquiterpenes, diterpenic carboxylic acid methyl esters and high levels of β-caryophyllene. Thus, it can be assumed that the oil resin and volatile and resinous fractions from the commercial product are not genotoxic or mutagenic.     

Biostimulant activity of humic-like substances from agro-industrial waste on Chlorella vulgaris and Scenedesmus quadricauda

The use of microalgae in a number of sectors, including biodiesel, feed and food production, is proving to be of great interest. An evaluation was made of the possible biostimulant effects on Chlorella vulgaris and Scenedesmus quadricauda of humic-like substances (HLs) extracted from agro-industrial wastes. These included digestate from the waste of an agro-livestock farm (D-HL), oil extraction residues from rape (B-HL, Brassica napus L.) and tomato residues (T-HL). The microalgal growth medium (BG11) was supplemented with HLs to evaluate their effect on biomass yield as well as carbohydrate, chlorophylls a and b, lipid and fatty acid contents. Our results showed that the HLs used in the test are effective biostimulants of C. vulgaris and S. quadricauda. The biostimulant effect seems to depend on the type of extract used for cultivating the microalgae, the concentration and the species treated. Among the extracts applied to the growth medium, D-HL and T-HL seem to have a significant effect on microalgal biomass and lipid production. Although B-HL showed no significant effect on the biomass and lipid content of C. vulgaris and S. quadricauda, its presence in the growth medium increased the saturated:unsaturated fatty acid ratio (SFA/UFA) and stimulated the sugar metabolism of the microalgae by increasing their carbohydrate and chlorophyll content.     

Geothermally warmed soils reveal persistent increases in the respiratory costs of soil microbes contributing to substantial C losses

Increasing temperatures can accelerate soil organic matter decomposition and release large amounts of CO₂ to the atmosphere, potentially inducing positive warming feedbacks. Alterations to the temperature sensitivity and physiological functioning of soil microorganisms may play a key role in these carbon (C) losses. Geothermally active areas in Iceland provide stable and continuous soil temperature gradients to test this hypothesis, encompassing the full range of warming scenarios projected by the Intergovernmental Panel on Climate Change for the northern region. We took soils from these geothermal sites 7 years after the onset of warming and incubated them at varying temperatures and substrate availability conditions to detect persistent alterations of microbial physiology to long-term warming. Seven years of continuous warming ranging from 1.8 to 15.9 °C triggered a 8.6–58.0% decrease on the C concentrations in the topsoil (0–10 cm) of these sub-arctic silt-loam Andosols. The sensitivity of microbial respiration to temperature (Q₁₀) was not altered. However, soil microbes showed a persistent increase in their microbial metabolic quotients (microbial respiration per unit of microbial biomass) and a subsequent diminished C retention in biomass. After an initial depletion of labile soil C upon soil warming, increasing energy costs of metabolic maintenance and resource acquisition led to a weaker capacity of C stabilization in the microbial biomass of warmer soils. This mechanism contributes to our understanding of the acclimated response of soil respiration to in situ soil warming at the ecosystem level, despite a lack of acclimation at the physiological level. Persistent increases in the respiratory costs of soil microbes in response to warming constitute a fundamental process that should be incorporated into climate change-C cycling models.