29 research outputs found

    Leptin Reduces the Expression and Increases the Phosphorylation of the Negative Regulators of GLUT4 Traffic TBC1D1 and TBC1D4 in Muscle of ob/ob Mice

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    Leptin improves insulin sensitivity in skeletal muscle. Our goal was to determine whether proteins controlling GLUT4 traffic are altered by leptin deficiency and in vivo leptin administration in skeletal muscle of wild type and ob/ob mice. Leptin-deficient ob/ob mice were divided in three groups: control, leptin-treated (1 mg/kg/d) and leptin pair-fed ob/ob mice. Microarray analysis revealed that 1,546 and 1,127 genes were regulated by leptin deficiency and leptin treatment, respectively. Among these, we identified 24 genes involved in intracellular vesicle-mediated transport in ob/ob mice. TBC1 domain family, member 1 (Tbc1d1), a negative regulator of GLUT4 translocation, was up-regulated (P = 0.001) in ob/ob mice as compared to wild types. Importantly, leptin treatment reduced the transcript levels of Tbc1d1 (P<0.001) and Tbc1d4 (P = 0.004) in the leptin-treated ob/ob as compared to pair-fed ob/ob animals. In addition, phosphorylation levels of TBC1D1 and TBC1D4 were enhanced in leptin-treated ob/ob as compared to control ob/ob (P = 0.015 and P = 0.023, respectively) and pair-fed ob/ob (P = 0.036 and P = 0.034, respectively) mice. Despite similar GLUT4 protein expression in wild type and ob/ob groups a different immunolocalization of this protein was evidenced in muscle sections. Leptin treatment increased GLUT4 immunoreactivity in gastrocnemius and extensor digitorum longus sections of leptin-treated ob/ob mice. Moreover, GLUT4 protein detected in immunoprecipitates from TBC1D4 was reduced by leptin replacement compared to control ob/ob (P = 0.013) and pair-fed ob/ob (P = 0.037) mice. Our findings suggest that leptin enhances the intracellular GLUT4 transport in skeletal muscle of ob/ob animals by reducing the expression and activity of the negative regulators of GLUT4 traffic TBC1D1 and TBC1D4

    Metabolic constituents of grapevine and grape-derived products

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    The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology

    Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer

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    Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.Peer reviewe

    Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer

    Get PDF
    Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer

    Paeoniflorin regulates macrophage activation in dimethylnitrosamine-induced liver fibrosis in rats

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    <p>Abstract</p> <p>Background</p> <p>Macrophages in other organs (e.g. kidneys, lungs, and spleen, et. al) have rarely been reported in the development of liver fibrosis. Therefore, it is important to investigate macrophage activation in the main organs in liver fibrosis. We investigated the potential antifibrogenic effects of paeoniflorin (PF) in a dimethylnitrosamine (DMN)-induced rat model with special focus on inhibiting macrophage activation in the main organs.</p> <p>Methods</p> <p>Rat hepatic fibrosis was induced by treatment with DMN three times weekly over a 4-week period. DMN rats were treated with water, PF, or gadolinium chloride (GdCl<sub>3</sub>) from the beginning of the 3<sup>rd</sup> week. The expression of CD68, marker of macrophage, was investigated using immunohistochemical, real-time PCR, and western blot analysis.</p> <p>Results</p> <p>Hepatic hydroxyproline content markedly decreased and histopathology improved in the DMN-PF rats. Expression of desmin and collagen 1 decreased notably in DMN-PF liver. CD68 expression in the liver, spleen and kidney increased markedly after 2 weeks but decreased in DMN-water rats. PF and GdCl<sub>3</sub> decreased CD68 expression in the liver and spleen and there was no effect on kidney. CD68 expression in the lung increased gradually during the course of DMN-induced liver fibrosis, and PF inhibited CD68 expression in the lung significantly while GdCl<sub>3</sub> increased CD68 markedly. Expression of tumor necrosis factor (TNF-α) was decreased significantly by GdCl<sub>3</sub> in the liver, as revealed by real-time PCR analysis. However, GdCl<sub>3</sub> could not decrease TNF-α level in the serum by enzyme linked immunosorbent assay (ELISA).</p> <p>Conclusions</p> <p>Macrophage activation was disrupted in the liver, spleen, lung and kidney during development of DMN-induced liver fibrosis. PF administration attenuated DMN-induced liver fibrosis at least in part by regulating macrophage disruption in the main organs.</p

    Amplification of the flgE gene provides evidence for the existence of a Brazilian borreliosis

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    INTRODUCTION: The symptoms of Brazilian borreliosis resemble the clinical manifestations of Lyme disease (LD). However, there are differences between the two in terms of epidemiological and laboratory findings. Primers usually employed to diagnose LD have failed to detect Borrelia strains in Brazil. OBJECTIVE: We aimed to identify the Brazilian Borrelia using a conserved gene that synthesizes the flagellar hook (flgE) of Borrelia burgdorferi sensu lato. METHOD: Three patients presenting with erythema migrans and positive epidemiological histories were recruited for the study. Blood samples were collected, and the DNA was extracted by commercial kits. RESULTS: The gene flgE was amplified from DNA of all selected patients. Upon sequencing, these positive samples revealed 99% homology to B. burgdorferi flgE. CONCLUSION: These results support the existence of borreliosis in Brazil. However, it is unclear whether this borreliosis is caused by a genetically modified B. burgdorferi sensu stricto or by a new species of Borrelia spp
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