Project description:Obesity is a chronic inflammatory disease that weakens macrophage innate immune response to infections. Since M1 polarization is crucial during acute infectious diseases, we hypothesized that diet-induced obesity inhibits M1 polarization of macrophages in the response to bacterial infection. Using a computational approach in conjunction with microarray data, we identified switching genes that may differentially control the behavior of response pathways in macrophages from lean and obese mice. Bone marrow macrophages (BMMM-NM-&) from lean and obese mice were exposed to live Porphyromonas gingivalis (P. gingivalis) for three incubation times (1 h, 4 h and 24 h). cDNA from BMMM-NM-& of lean and obese mice were hybridized on Affymetrix Mouse Genome 430 2.0 Arrays. Hybridization was performed on three replicates at each time point (18 arrays total).
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:Thiazolidinediones increase tissue insulin sensitivity and are protective against worsening of nephropathy and hypertension in diabetes. Mechanisms underlying protection at the renal level likely involve a variety of unknown changes in gene expression. We examined kidney gene expression in obese and lean Zucker rats in response to rosiglitazone (Avandia®), a peroxisome proliferator activated receptor (gamma-subtype) agonist. Lean and obese Zucker rats were treated with either control chow or chow with added rosiglitazone (3 mg/kg�bw) for 12 weeks (n = 3/group). Total kidney mRNA expression was evaluated using the Affymetrix Rat Genome 230 2.0 GeneChip. 903 probe sets were significantly (P < 0.05) altered with at least 1.5-fold changes between groups. In untreated obese rats, 300 probe sets were increased and 244 decreased, relative to lean. Increased genes included the β-subunit of the epithelial sodium channel (ENaC), the thiazide-sensitive Na-Cl cotransporter, and aquaporin 3. Decreased genes included angiotensin converting enzyme, type 1 (ACE1). FatiGO analysis showed that the highest number of altered genes between lean and obese belonged to the categories: ion binding, hydrolase activity, and protein binding. RGZ increased expression of uncoupling protein 1 (UCP1), CD36, and fatty acid binding protein 4 (FAbp4) in both lean and obese rats. In obese rats, 33 genes were normalized by RGZ (no longer different from lean) including ACE1, fatty acid synthase (Fasn), and stearoyl-coenzyme A desaturase 2 (Scd2). Ingenuity Pathways System analysis of genes upregulated by RGZ in obese rats revealed two major nodes affected: PPAR-gamma and tumor necrosis factor alpha (TNF-alpha). Experiment Overall Design: Twelve male Zucker rats (6 Lean and 6 Obese) were used in the study. Three rats from each body type were fed either with control diet (ground chow diet) or control diet with rosiglitazone (3 mg/kg body weight). The rats were weighed weekly and fed diets and recieved water ad libitum for 12 weeks.
Project description:Here, we developed a mouse model of diet induced obesity that is graft competent. In this model, we grew an ER-positive breast cancer patient derived tumor. Following ovariectomy and estrogen deprivation therapy, tumors continued to grow in obese but not lean mice. RNAsequencing analysis was performed on tumors from estrogen-supplemented lean mice, and from lean and obese mice after estrogen deprivation. This analysis identified fibroblast growth factor receptor signaling as a potential driver of tumor progression in the context of obesity.
Project description:To assess changes in expression level of various chemokines and their receptors on diet-induced obesity, we analysed gene expression in adipose tissue of C56BL/6J mice fed a high-fat (HF) diet or normal chow diet for 8 weeks. HF diet-induced obese (DIO) mice showed adipose tissue inflammation and insulin resistance. Comprehensive gene expression analysis showed that MCP-1–CCR2 and CCL5–CCR5 signalling in epididymal white adipose tissue (eWAT) were enhanced during the development of obesity. Surprisingly, the gene expression of Cx3cl1 was decreased in the eWAT of DIO mice compared with lean mice. While Cx3cr1 expression showed no significant difference between DIO and lean mice. Decreased CX3CL1-CX3CR1 signalling in adipose tissue may also be involved in the development of obesity-induced adipose tissue inflammation and insulin resistance.
Project description:Livers of diet induced obese and lean wildtype and ChemR23 knocout mice injected with and without resolvin E1 (RvE1) were run on the NovaSeq 6000 for total mRNA sequencing.
Project description:High-fat diet (HFD) decreases insulin sensitivity. How high-fat diet causes insulin resistance is largely unknown. Here, we show that lean mice become insulin resistant after being administered exosomes isolated from the feces of obese mice fed a high-fat diet (HFD) or from human type II diabetic patients with diabetes. HFD altered the lipid composition of exosomes from predominantly PE in exosomes from lean animals (L-Exo) to PC in exosomes from obese animals (H-Exo). Mechanistically, we show that intestinal H-Exo is taken up by macrophages and hepatocytes, leading to inhibition of the insulin signaling pathway. Moreover, exosome-derived PC binds to and activates AhR, leading to inhibition of the expression of genes essential for activation of the insulin signaling pathway, including IRS-2, and its downstream genes PI3K and Akt. Together, our results reveal HFD-induced exosomes as potential contributors to the development of insulin resistance. Intestinal exosomes thus have potential as broad therapeutic targets.
Project description:Three different macrophage subsets and one subpopulation of monocyte derived cells were sorted from lean and obese mice adipose tissue