PON2 Deficiency Leads to Increased Susceptibility to Diet-Induced Obesity.

(1) Background: Paraoxonase 2 (PON2) is a ubiquitously expressed protein localized to endoplasmic reticulum and mitochondria. Previous studies have shown that PON2 exhibits anti-oxidant and anti-inflammatory functions, and PON2-deficient (PON2-def) mice are more susceptible to atherosclerosis. Furthermore, PON2 deficiency leads to impaired mitochondrial function. (2) Methods: In this study, we examined the susceptibility of PON2-def mice to diet-induced obesity. (3) Results: After feeding of an obesifying diet, the PON2-def mice exhibited significantly increased body weight due to increased fat mass weight as compared to the wild-type (WT) mice. The increased adiposity was due, in part, to increased adipocyte hypertrophy. PON2-def mice had increased fasting insulin levels and impaired glucose tolerance after diet-induced obesity. PON2-def mice had decreased oxygen consumption and energy expenditure. Furthermore, the oxygen consumption rate of subcutaneous fat pads from PON2-def mice was lower compared to WT mice. Gene expression analysis of the subcutaneous fat pads revealed decreased expression levels of markers for beige adipocytes in PON2-def mice. (4) Conclusions: We concluded that altered systemic energy balance, perhaps due to decreased beige adipocytes and mitochondrial dysfunction in white adipose tissue of PON2-def mice, leads to increased obesity in these mice

Deposition of tin oxide, iridium and iridium oxide films by metal-organic chemical vapor deposition for electrochemical wastewater treatment

In this research, the specific electrodes were prepared by metal-organic chemical vapor deposition (MOCVD) in a hot-wall CVD reactor with the presence of O2 under reduced pressure. The Ir protective layer was deposited by using (Methylcyclopentadienyl) (1,5-cyclooctadiene) iridium (I), (MeCp)Ir(COD), as precursor. Tetraethyltin (TET) was used as precursor for the deposition of SnO2 active layer. The optimum condition for Ir film deposition was at 300 °C, 125 of O2/(MeCp)Ir(COD) molar ratio and 12 Torr of total pressure. While that of SnO2 active layer was at 380 °C, 1200 of O2/TET molar ratio and 15 Torr of total pressure. The prepared SnO2/Ir/Ti electrodes were tested for anodic oxidation of organic pollutant in a simple three-electrode electrochemical reactor using oxalic acid as model solution. The electrochemical experiments indicate that more than 80% of organic pollutant was removed after 2.1 Ah/L of charge has been applied. The kinetic investigation gives a two-step process for organic pollutant degradation, the kinetic was zero-order and first-order with respect to TOC of model solution for high and low TOC concentrations, respectively

ReCROP: bioinocula and CROPping systems: an integrated biotechnological approach for improving crop yield, biodiversity and REsilience of Mediterranean agro-ecosystems

The Mediterranean economy is highly dependent on agriculture. However, agricultural sustainability and productivity in this region is under serious threat due to climate change and the depletion of water resources. This is worsened by poor management practices, such as the overuse of chemical fertilizers, pesticides, overgrazing and monoculture farming. Recent climate change models indicate that European and Northern African regions will undergo extreme climatic events throughout the year, this will negatively impact crop yield and productivity. Summer droughts and heat waves periods will increase for most parts of Europe, as well as short intense rain events. Preserving and improving productive agricultural land in this region is vital, especially through the application of sustainable soil and crop management practices that promote soil fertility and water conservation; this will improve resilience to degradation and to extreme climatic events. ReCROP is a European project that aims to identify sustainable and resilient agricultural production systems in the Mediterranean region through the combined use of biotechnological tools, such as bioinoculants, and environmentally friendly agronomic practices. ReCROP will assess different agroecosystems with key local crops (i.e vineyards, maize and aromatic/medicinal plants) of the Mediterranean region under field conditions to help improve crop resilience, yield, water conservation and soil health under the current scenario of climate change. Soil organisms play a key role in ecosystem processes, leading to essential soil functions and are used as bioindicators of soil quality. Their monitoring is crucial to assess the impact of beneficial agricultural practices on soil functioning. One of the goals of ReCROP will be to evaluate the beneficial impact of different agricultural practices on the structural and functional soil diversity at different levels of the soil food web. The macrofauna and mesofauna (i.e springtails and mites) as well as microbial biomass, activity and biodiversity of soil microbial communities (bacteria, archaea, fungi) will be monitored with a special effort to produce a multitaxa index of soil biological quality. This work will contribute to identify which practices are beneficial for the biodiversity of Mediterranean agricultural soils, thus providing resistance and resilience, in terms of soil functioning and against soil disturbances.info:eu-repo/semantics/publishedVersio

Interleukin-1 regulates multiple atherogenic mechanisms in response to fat feeding

Background: Atherosclerosis is an inflammatory process that develops in individuals with known risk factors that include hypertension and hyperlipidaemia, influenced by diet. However, the interplay between diet, inflammatory mechanisms and vascular risk factors requires further research. We hypothesised that interleukin-1 (IL-1) signaling in the vessel wall would raise arterial blood pressure and promote atheroma. Methodology/Principal Findings: Apoe(-/-) and Apoe(-/-)/IL-1R1(-/-) mice were fed high fat diets for 8 weeks, and their blood pressure and atherosclerosis development measured. Apoe(-/-)/IL-R1(-/-) mice had a reduced blood pressure and significantly less atheroma than Apoe(-/-) mice. Selective loss of IL-1 signaling in the vessel wall by bone marrow transplantation also reduced plaque burden (p<0.05). This was associated with an IL-1 mediated loss of endothelium-dependent relaxation and an increase in vessel wall Nox 4. Inhibition of IL-1 restored endothelium-dependent vasodilatation and reduced levels of arterial oxidative stress. Conclusions/Significance: The IL-1 cytokine system links atherogenic environmental stimuli with arterial inflammation, oxidative stress, increased blood pressure and atherosclerosis. This is the first demonstration that inhibition of a single cytokine can block the rise in blood pressure in response to an environmental stimulus. IL-1 inhibition may have profound beneficial effects on atherogenesis in man

A novel approach to measure mitochondrial respiration in frozen biological samples.

Respirometry is the gold standard measurement of mitochondrial oxidative function, as it reflects the activity of the electron transport chain complexes working together. However, the requirement for freshly isolated mitochondria hinders the feasibility of respirometry in multi-site clinical studies and retrospective studies. Here, we describe a novel respirometry approach suited for frozen samples by restoring electron transfer components lost during freeze/thaw and correcting for variable permeabilization of mitochondrial membranes. This approach preserves 90-95% of the maximal respiratory capacity in frozen samples and can be applied to isolated mitochondria, permeabilized cells, and tissue homogenates with high sensitivity. We find that primary changes in mitochondrial function, detected in fresh tissue, are preserved in frozen samples years after collection. This approach will enable analysis of the integrated function of mitochondrial Complexes I to IV in one measurement, collected at remote sites or retrospectively in samples residing in tissue biobanks

Insulin Resistance and Altered Systemic Glucose Metabolism in Mice Lacking Nur77

OBJECTIVE: Nur77 is an orphan nuclear receptor with pleotropic functions. Previous studies have identified Nur77 as a transcriptional regulator of glucose utilization genes in skeletal muscle and gluconeogenesis in liver. However, the net functional impact of these pathways is unknown. To examine the consequence of Nur77 signaling for glucose metabolism in vivo, we challenged Nur77 null mice with high-fat feeding. RESEARCH DESIGN AND METHODS: Wild-type and Nur77 null mice were fed a high-fat diet (60% calories from fat) for 3 months. We determined glucose tolerance, tissue-specific insulin sensitivity, oxygen consumption, muscle and liver lipid content, muscle insulin signaling, and expression of glucose and lipid metabolism genes. RESULTS: Mice with genetic deletion of Nur77 exhibited increased susceptibility to diet-induced obesity and insulin resistance. Hyperinsulinemic-euglycemic clamp studies revealed greater high-fat diet–induced insulin resistance in both skeletal muscle and liver of Nur77 null mice compared with controls. Loss of Nur77 expression in skeletal muscle impaired insulin signaling and markedly reduced GLUT4 protein expression. Muscles lacking Nur77 also exhibited increased triglyceride content and accumulation of multiple even-chained acylcarnitine species. In the liver, Nur77 deletion led to hepatic steatosis and enhanced expression of lipogenic genes, likely reflecting the lipogenic effect of hyperinsulinemia. CONCLUSIONS: Collectively, these data demonstrate that loss of Nur77 influences systemic glucose metabolism and highlight the physiological contribution of muscle Nur77 to this regulatory pathway.National Institutes of Health (HD-00850, DK-081683-01, DK-30425, HL030568); American Diabetes Associatio

Lysosome-mediated processing of chromatin in senescence

Cellular senescence is a stable proliferation arrest, a potent tumor suppressor mechanism, and a likely contributor to tissue aging. Cellular senescence involves extensive cellular remodeling, including of chromatin structure. Autophagy and lysosomes are important for recycling of cellular constituents and cell remodeling. Here we show that an autophagy/lysosomal pathway processes chromatin in senescent cells. In senescent cells, lamin A/C–negative, but strongly γ-H2AX–positive and H3K27me3-positive, cytoplasmic chromatin fragments (CCFs) budded off nuclei, and this was associated with lamin B1 down-regulation and the loss of nuclear envelope integrity. In the cytoplasm, CCFs were targeted by the autophagy machinery. Senescent cells exhibited markers of lysosomal-mediated proteolytic processing of histones and were progressively depleted of total histone content in a lysosome-dependent manner. In vivo, depletion of histones correlated with nevus maturation, an established histopathologic parameter associated with proliferation arrest and clinical benignancy. We conclude that senescent cells process their chromatin via an autophagy/lysosomal pathway and that this might contribute to stability of senescence and tumor suppression

Dynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation by using inlet glass fibers injection response and application to polymers degassing

International audienceIn this paper is described an original dynamic model of a reactive co-rotating twinscrew extrusion (TSE) process operated by the Rhodia company for the Nylon-66 degassing finishing step. In order to validate the model, dynamic experiments have been performed on a small-scale pilot plant. These experiments consist in a temporary injection of glass fibers at the inlet of the extruder after it has reached a given operating point. The outlet glass fibers mass fraction time variation is then measured. This experiment does not lead to the RTD measurement. As a matter of fact, due to the high quantity of glass fibers that is introduced, the behavior of the flow through the extruder is perturbed so that the glass fibers cannot be considered as an inert tracer. The dynamic model that we have published elsewhere (Choulak et al., Ind. Eng. Chem. Res., 2004, 43(23), 7373-7382) is adapted to take into account this nonlinear behavior of the extruder with respect to the glass fibers injection and is favorably compared to experimental results. The description of the degassing operation is also included in the model. The model allows simulations of the complete dynamic behavior of the process. When the steady state is reached, the good position of the degassing vent with respect to the partially and fully filled zones positions can also be checked, thus illustrating the way the model can be used for design purposes

Leaf yellowing of the wheat cultivar Mace in the absence of yellowspot disease

The wheat variety Mace is currently dominating the southern wheat growing regions of Australia. It is high yielding in most environments and resistant to many diseases including yellow spot (also known as tan spot). However, observations of foliar yellowing of Mace have recently been reported in the field. This has raised concerns over a possible breakdown of resistance to yellow spot, which is caused by the necrotrophic fungal pathogen Pyrenophora triticirepentis. West Australian field samples of yellowing Mace leaves were evaluated for P. triticirepentis infection, and this pathogen was determined to be absent. Instead, Alternaria spp. were isolated from the wheat leaves. Pathogenicity assays showed that the recovered Alternaria spp. were unable to cause disease symptoms on Mace. Furthermore, spontaneous foliar lesions were observed in Mace grown in the absence of pathogens. It is therefore likely that such yellowing is a physiological trait, which will not respond to fungicide application. A marginal impact on yield cannot be excluded