Project description:SGBS cells were used as a model system to investigate the cellular mode of action of a variety of plasticizers in human adipocytes. In brief, cells were cultured at 5% CO2 and 37°C in 95% humidity. Cells of generation 40 and passage 3 after thawing were grown to confluence with DMEM/F12 containing 33 µM biotin, 17 µM pantothenate, 100 U/l penicillin, and 0.1 mg/l streptomycin (basal medium) supplemented with 10% FCS (Gibco, Carlsbad, CA, USA). According to the standard differentiation protocol, differentiation was initiated (day 0) after changing to serum-free basal medium supplemented with 0.1 μM cortisol, 0.01 mg/ml apo-transferrin, 0.2 nM triiodothyronine, and 20 nM human insulin (differentiation medium) with the addition of 2 µM rosiglitazone, 25 nM dexamethasone, and 200 µM 3-isobutyl-1-methylxanthine for the first four days. The positive control was differentiated using the standard protocol with rosiglitazone. For plasticizer treatments, differentiation was conducted without rosiglitazone and cells were continuously exposed from day 0 – day 16 to the plasticizers or their transformation products. As for plasticizer treatments, the negative control was differentiated with rosiglitazone-free medium containing equivalent amounts of solvent (0.01 MeOH, v/v) for 16 days, resulting in minimal differentiation. All media were renewed every second day to mimic continuous exposure.
Project description:In our earlier study, it was shown that Rosiglitazone enhances the brown adipogenesis of Immortalized Human Bone Marrow Mesenchymal Stromal Cells - hTERT (iMSC3). The current study compared the transcriptomics profiles of the different adipocytes derived from iMSC3 reported in our previous study. The complete transcriptomic profiles of iMSCs and adipocytes differentiated with and without Rosiglitazone treatment revealed a set of marker genes that warrant further investigation. The transcriptomics analysis revealed the upregulation and uniquely expression of genes due to Rosiglitazone treatment seems to have roles in brown adipogenesis.
Project description:Human multipotent adipose-derived stem (hMADS) cells are differentiated in white or brown adipocytes with Rosiglitazone between days 14 and 18. PPAR alpha was silenced by siRNA transfections at day 10.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:This study aimed at determining the transcriptional changes associated with the white-to-brown conversion of human mesenchymal adipose-derived stem cells firstly differentiated into white adipocytes (in the presence of rosiglitazone from day 2 to day 9). White differentiation was completed within 14 days, and PPARg (rosiglitazone) or PPARa (GW7647) agonists were added to the medium for 4 additional days to induce the brown phenotype. Cells were harvested at day 18 and processed for microarray experiments (Agilent).
Project description:Reprograming of 'white' to 'brite' adipocytes with higher oxidative capacity and improved endocrine function represents a potentially important approach to address the dysfunctional adipocyte phenotypes in obesity. We find that chronic treatment with the PPAR? agonist (rosiglitazone, 1 uM for 7days in vitro) in white human adipose tissue induced metabolic changes. Our trancriptome analysis showed that higher mitochondrial and peroxisomal fatty acid oxidation pathways and other genes involved in lipid metabolism including (re)esterification are induced by rosiglitazone treatment. To understand the biochemical basis of brite vs. white human adipocytes, we will perform comprehensive metabolomic profiling of control and rosiglitazone treated tissues using unbiased lipidomics approach.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.