ABSTRACT: In diabetics, methylglyoxal (MG), a glucose-derived metabolite, plays a noxious role by inducing oxidative stress, which causes and exacerbates a series of complications. With the use of microarray analysis, we comprehensively screened the gene expression profiles of ST2 cells, derived from a multipotent bone marrow stromal cell line, in the presence or absence of oxidative stress induced by100 M-NM-
Project description:In diabetics, methylglyoxal (MG), a glucose-derived metabolite, plays a noxious role by inducing oxidative stress, which causes and exacerbates a series of complications. With the use of microarray analysis, we comprehensively screened the gene expression profiles of ST2 cells, derived from a multipotent bone marrow stromal cell line, in the presence or absence of oxidative stress induced by100 μM methylglyoxal (MG) treatment to charactrize genes related to diabetic complications.
Project description:Colorectal cancer (CRC) was induced in Foxp3/eGFP reporter mice by the azoxymethane/dextran sulphate sodium salt (AOM/DSS) protocol. Mice were injected i.p. with the procarcinogen AOM (12.5 mg/kg of body weight). After 1 week, mice received drinking water supplemented with 2.5% DSS for 5 to 7 days, followed by 2 weeks of regular water. The DSS administration was repeated twice with 2% DSS. Mice were sacrificed at week 11 and lamina propia lymphocytes (LPLs) from the colon were isolated. CD4+FOXP3+ (eGFP+) ST2+ or ST2- Tregs were separated from colonic LPLs of CRC induced mice using a FACSAria II cell sorter. Microarray analysis was performed to analyze if ST2+ FOXP3+ Tregs from the colon of CRC mice present a distinct transcription pattern compared to ST2- FOXP3+ Tregs. By this, the role of ST2 for Treg function during intestinal tumorigenesis should be characterized.
Project description:PPARM-NM-3 is a master transcriptional regulator of adipogenesis. Hence, the identification of PPARM-NM-3 coactivators should help reveal mechanisms controlling gene expression in adipose tissue development and physiology. We show that the non-coding RNA Steroid receptor RNA Activator, SRA, associates with PPARM-NM-3 and coactivates PPARM-NM-3-dependent reporter gene expression. Overexpression of SRA in ST2 adipocyte precursor cells promotes their differentiation into adipocytes. Conversely, knockdown of endogenous SRA inhibits 3T3-L1 preadipocyte differentiation. Microarray analysis reveals hundreds of SRA-responsive genes in adipocytes, including genes in cell cycle, insulin and TNFM-NM-1 signaling pathways. Some functions of SRA may involve mechanisms other than coactivation of PPARM-NM-3. SRA increases insulin-stimulated glucose uptake in adipocytes. SRA promotes S-phase entry during mitotic clonal expansion, decreases expression of cyclin-dependent kinase inhibiters p21Cip1 and p27Kip1, and increases phosphorylation of Cdk1/Cdc2. SRA also inhibits the TNFM-NM-1-induced phosphorylation of c-Jun NH2-terminal kinase. In conclusion, SRA enhances adipogenesis and adipocyte function through multiple pathways. Total RNA was isolated from fully differentiated (MDIT day 4) SRA overexpressing (pMSCV-SRA) and control (pMSCV empty vector) ST2 adipocytes, or fully differentiated (MDIT day 8) shSRA knockdown (pSuperior-shSRA) or shControl (pSuperior-shcontrol) 3T3-L1 adipocytes. Genome wide gene expression analysis was performed using Affymetrix mouse genome 430 2.0 arrays. Triplicate samples were analyzed.
Project description:ST2 heterodimerizes with IL-1RAcp to form the receptor for IL-33, which is primarily associated with allergic inflammation by inducing Th2 responses. Recently, however, IL-33 was found to be expressed in the central nervous system and in retinal Muller cells which imply functions, as yet undescribed, beyond Th2 mediated inflammation. Muller cells support the health of the retina and photoreceptors and are also involved in inflammation in retinal degeneration. It is not known how IL-33/ST2 functions in this capacity. We recently found that ST2 ko mice are protected from CLE-induced photoreceptor loss, implying a detrimental effect of IL33/ST2 in CLE. We wish to perform microarray analysis using WT and ST2 KO mice in CLE model to better understand the mechanism by which IL-33/ST2 regulates retinal degeneration. CLE (Constant Light Exposure) is a model of retinal damage/degeneration in mice. Mice are exposed to bright light 24 hours a day for a period of time which damages retina photoreceptors. This damage is assessed by histology, optical coherence tomography (OCT), which measures retina thickness in vivo. In this experiment, the WT and ST2 KO mice (5 mice per genotype per time point) will be exposed to 1200-lux constant light for 0, 3, 10 days. The retinal RNA will be isolated and analyzed for differential gene expression by microarray.
Project description:Methylglyoxal (MG) is a toxic byproduct of the glycolytic pathway and is quantitatively the most important precursor to advanced glycation end-products (AGEs). Insight into which proteins and in particular their individual modification sites are central to understand the involvement of MG and AGE in diabetes and aging related diseases. Here, we present a method to simultaneously monitor protein AGE formation in biological samples by employing an alkyne-labeled methylglyoxal probe. We apply the method to blood and plasma to demonstrate the impact of blood cell glyoxalase activity on plasma protein AGE formation. We move on to isolate proteins modified by the MG probe and accordingly can present the first general inventory of more than 100 proteins and 300 binding sites of the methylglyoxal probe on plasma as well as erythrocytic proteins.
Project description:SKM-1 cells were cultured for 28 days in the absence or presence of low doses of the DNMT1 inhibitors DAC (10 nM) or AZA (100 nM). The experiment was carried in two independent set at different times, and with 2 replicates for each condition (Ctl, AZA, DAC) for a total of 12 samples. The SKM-1 cell line is derived from secondary AML arising from MDS, and is one the few representative in vitro models of MDS.
Project description:Oncometabolites are of the utmost importance to our understanding of tumor initiation, progression and resistance to therapy. We previously demonstrated that methylglyoxal (MG), a reactive dicarbonyl spontaneously formed in glycolytic cancer cells, unexpectedly enhanced their metastatic potential. Here, using genome-wide DNA methylation analysis, we report that MG stress induced DNA methyltransferases (DNMTs) expression resulting in DNA hypermethylation in triple negative breast cancer cells. Interestingly, we observed that DNMT3B protein was stabilized upon MG stress. Consistently, MG stressed cells demonstrated a significant loss of tumor suppressor genes as assessed using integrated analysis of methylome and RNASeq data. Both 5-AZA demethylating agent and MG scavengers triggered the re-expression of representative silenced genes. We have delineated an epigenomic signature of MG stress that effectively provided survival stratification in breast cancer patients. This study emphasizes the importance of MG stress, occurring downstream of the Warburg effect, as a major epigenetic regulator and proposes MG scavengers to reverse altered patterns of gene expression associated with MG stress pro-cancer effects.
Project description:Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2’-deoxycytidine (5-Aza-2’) enhances transcription of tumor suppressor genes and induces replication errors via entrapment of DNMT1. Post-translational modification by SUMO plays major roles in the DNA damage response and is required for degradation of entrapped DNMT1. Here, we combine SUMOylation inhibitor TAK981 and DNA-hypomethylating agent 5-Aza-2’ to improve treatment of MYC driven hematopoietic malignancies, since MYC overexpressing tumors are sensitive to SUMOylation inhibition. We studied the classical MYC driven malignancy Burkitt lymphoma, as well as diffuse large B-cell lymphoma (DLBCL) with and without MYC translocation. SUMO inhibition prolonged the entrapment of DNMT1 to DNA, resulting in DNA damage. An increase in DNA damage was observed in cells co-treated with TAK981 and 5-Aza-2’. Both drugs synergized to reduce cell proliferation in vitro in a B cell lymphoma cell panel, including Burkitt lymphoma and DLBCL. In vivo experiments combining TAK981 (25 mg/kg) and 5-Aza-2’ (2.5 mg/kg) showed a significant reduction in outgrowth of Burkitt lymphoma in an orthotopic xenograft model. In contrast, single dosing of TAK981 was ineffective and single dosing of 5-Aza-2’ only led to a modest outgrowth reduction. TAK981 and 5-Aza-2’ synergize to reduce B cell Lymphoma outgrowth in vitro and in vivo. SUMOylation is a key-player in the repair of DNA damage, hence upon TAK981 treatment the repair of DNA damage induced by 5-Aza-2’ treatment is impaired. Our results demonstrate the potential of tailored combination of drugs, based on insight in molecular mechanisms, to improve the efficacy of cancer therapies.