Project description:Bisphenol A (BPA) is a xenobiotic endocrine disrupting chemical. In vitro and in vivo studies indicated that BPA alters endocrine-metabolic pathways in adipose tissue increasing the risk of developing metabolic disorders. BPA effects on human adipocytes, specifically in children, are poorly investigated. To investigate in childhood the effect of exposure to BPA on metabolic disorders we analyzed in vitro the effects of environmentally relevant doses of BPA on gene expression of mature human adipocytes from pre-pubertal lean patients and on related physiological outcomes. Adipocytes from children were treated in vitro with BPA and gene expression was evaluated by qRT-PCR. Genome wide analyses were performed using GeneChip Human Gene 1.0 ST array. Lipid content in adipocytes was estimated by ORO staining and Triglyceride Quantification Kit. Secreted IL-1beta, in adipocytes culture medium, and insulin, in PANC-1 culture medium, were performed using ELISA assays. BPA was found to promote up-regulation of ER? and ERR?, and down-regulation of GPR30 expression modulating estrogen signaling and following a non-linear dose-response. Microarray data analysis demonstrated that BPA increases the gene expression of pro-inflammatory cytokines and lipid metabolism-related FABP4 and CD36 in adipocytes. PCSK1 resulted the most interesting gene being down-regulated by BPA thus impairing insulin production in pancreas. BPA promotes inflammation and lipid metabolism dysregulation in adipocytes from lean children. Moreover, PCSK1 can be a key gene in BPA action modulating insulin production. Exposure to BPA in childhood may be an important risk factor in developing obesity and metabolic disorders. Three prototypic situations were analyzed (5 replication each): untreated cells (C), 10 nM BPA treated cells (BPA), 1 nM 17-beta Estradiol treated cells (ES).
Project description:Bisphenol A (BPA) is a xenobiotic endocrine disrupting chemical. In vitro and in vivo studies indicated that BPA alters endocrine-metabolic pathways in adipose tissue increasing the risk of developing metabolic disorders. BPA effects on human adipocytes, specifically in children, are poorly investigated. To investigate in childhood the effect of exposure to BPA on metabolic disorders we analyzed in vitro the effects of environmentally relevant doses of BPA on gene expression of mature human adipocytes from pre-pubertal lean patients and on related physiological outcomes. Adipocytes from children were treated in vitro with BPA and gene expression was evaluated by qRT-PCR. Genome wide analyses were performed using GeneChip® Human Gene 1.0 ST array. Lipid content in adipocytes was estimated by ORO staining and Triglyceride Quantification Kit. Secreted IL-1β, in adipocytes culture medium, and insulin, in PANC-1 culture medium, were performed using ELISA assays. BPA was found to promote up-regulation of ERα and ERRγ, and down-regulation of GPR30 expression modulating estrogen signaling and following a non-linear dose-response. Microarray data analysis demonstrated that BPA increases the gene expression of pro-inflammatory cytokines and lipid metabolism-related FABP4 and CD36 in adipocytes. PCSK1 resulted the most interesting gene being down-regulated by BPA thus impairing insulin production in pancreas. BPA promotes inflammation and lipid metabolism dysregulation in adipocytes from lean children. Moreover, PCSK1 can be a key gene in BPA action modulating insulin production. Exposure to BPA in childhood may be an important risk factor in developing obesity and metabolic disorders.
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: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.
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.