Project description:Orchestrated recruitment of neutrophils to inflamed tissue is essential during initiation of inflammation. Inflamed areas are usually hypoxic, and adaptation to reduced oxygen pressure is typically mediated by hypoxia pathway proteins. However, it is still unclear how these factors influence the migration of neutrophils to and at the site of inflammation either during their transmigration through the blood-endothelial cell barrier, or their motility in the interstitial space. Here, we reveal that activation of the Hypoxia Inducible Factor-2 (HIF2α) due to deficiency of HIF-prolyl hydroxylase domain protein-2 (PHD2) boosts neutrophil migration specifically through highly confined microenvironments. In vivo, the increased migratory capacity of PHD2-deficient neutrophils resulted in massive tissue accumulation in acute local inflammation. Using systematic RNAseq analyses and mechanistic approaches, we identified RhoA, a cytoskeleton organizer, as the central downstream factor that mediates HIF2α-dependent neutrophil motility. Thus, we propose that the here identified novel PHD2-HIF2α-RhoA axis is vital to the initial stages of inflammation as it promotes neutrophil movement through highly confined tissue landscapes.
Project description:Obesity and insulin resistance are associated with oxidative stress, which may be implicated in their progression. The kinase JNK1 emerged as a promising drug target for the treatment of obesity and type-2 diabetes. However, JNK1 is a key mediator of the oxidative stress response, promoting either cell dead or survival depending on magnitude and context of its activation. Furthermore, JNK inactivation shortens lifespan in drosophila and c. elegans. To learn on the safety and efficacy of long-term JNK inhibition in vertebrates, we investigated mice lacking JNK1 (JNK1-/-) exposed over a long period to an obesogenic high-fat diet (HFD). JNK1-/- mice chronically fed an HFD developed more skin oxidative damage because of reduced catalase expression, but also showed sustained protection from obesity, adipose tissue inflammation, steatosis, and insulin resistance, paralleled by decreased oxidative damage in fat and liver. We conclude that JNK1 is a relatively safe drug target for obesity-related diseases. RNA was collected from liver, skin and epididymal fat tissues from JNK1 KO mice and WT mice fed in high fat diet. Each condition was run in quadruplicate
Project description:Obesity is associated with severe, difficult to control asthma, and increased airway oxidative stress. Mitochondrial reactive oxygen species (mROS) are an important source of oxidative stress leading us to hypothesize that targeting mROS in obese allergic asthma might be an effective treatment strategy. Using a mouse model of house dust mite (HDM) induced allergic airway disease in mice fed a low- (LFD) or high-fat diet (HFD), and the mitochondrial antioxidant MitoQuinone (MitoQ); we investigated the effects of obesity and mROS on airway inflammation, remodelling and airway hyperreactivity (AHR). HDM induces airway inflammation, remodelling and hyperreactivity in both lean and obese mice. Obese allergic mice showed increased lung tissue eotaxin levels, airway tissue eosinophilia and AHR when compared to lean allergic mice. MitoQ reduced markers of airway inflammation, remodelling and hyperreactivity in both lean and obese allergic mice, and tissue eosinophilia in obeseHDM mice. mROS regulates cell signalling by protein oxidation of multiple downstream targets: MitoQ reduced HDM-induced cysteine-sulfenylation of several proteins including those involved in the unfolded protein response (UPR). In summary, mROS mediates the development of allergic airway disease and hence MitoQ might be effective for the treatment for asthma, and specific features of obese asthma.
Project description:Currently, there are no established treatments for NAFLD/NASH. Treatment recommendations include weight reduction through both diet and physical exercise, and weight-loss surgery for extreme obesity. Most medical regimens target components of the metabolic syndrome or oxidative stress associated with the pathogenesis of NASH. These include anti-obesity regimens, insulin sensitizers, anti-hyperlipidemics, and antioxidants. Thus, a need exists to validate approaches that might help the development and progression of hepatic steatosis, oxidative stress, and inflammation in association with NAFLD.
2017-01-01 | GSE77964 | GEO
Project description:Inflammation induced oxidative stress mediates gene fusion formation in prostate cancer
Project description:Obesity and insulin resistance are associated with oxidative stress, which may be implicated in their progression. The kinase JNK1 emerged as a promising drug target for the treatment of obesity and type-2 diabetes. However, JNK1 is a key mediator of the oxidative stress response, promoting either cell dead or survival depending on magnitude and context of its activation. Furthermore, JNK inactivation shortens lifespan in drosophila and c. elegans. To learn on the safety and efficacy of long-term JNK inhibition in vertebrates, we investigated mice lacking JNK1 (JNK1-/-) exposed over a long period to an obesogenic high-fat diet (HFD). JNK1-/- mice chronically fed an HFD developed more skin oxidative damage because of reduced catalase expression, but also showed sustained protection from obesity, adipose tissue inflammation, steatosis, and insulin resistance, paralleled by decreased oxidative damage in fat and liver. We conclude that JNK1 is a relatively safe drug target for obesity-related diseases.
Project description:Obesity during pregnancy is related to adverse maternal and neonatal outcomes. Factors involved in these outcomes may include increased maternal insulin resistance, inflammation, oxidative stress and nutrient mishandling. The placenta is the primary determinant of fetal outcomes, and its function can be impacted by maternal obesity. The aim of this study in mice was to determine the effect of obesity on maternal lipid handling, inflammatory and redox state, and placental oxidative stress, inflammatory signalling, and gene expression relative to female and male fetal growth. Here we showed that HFHS diet induced, in the dams, hepatic steatosis, oxidative stress (reduced catalase, elevated protein oxidation) and activation of pro-inflammatory pathways (p38-MAPK) along with imbalanced circulating cytokine concentrations (increased IL-6 and decreased IL-5 and IL-17A). HFHS fetuses were asymmetrically growth-restricted, showing sex-specific changes in circulating cytokines (GM-CSF, TNF-a, IL-6 and IFN-g). Morphology of the placenta Lz was modified by a HFHS diet, in association with sex-specific alterations in the expression of genes and proteins implicated in oxidative stress, inflammation, and stress signalling. Placental gene expression changes were comparable to that seen in models of intrauterine inflammation and were related to a transcriptional network involving transcription factors, LYL1 and PLAG1. In summary, this study shows that fetal growth restriction with maternal obesity is related to elevated oxidative stress, inflammatory pathways, and sex-specific placental changes. Our data are important given the marked consequences and the rising rates of obesity worldwide.