title: Estrogen receptor 1 agonist PPT stimulates Slc2a4 gene expression and improves insulin-induced glucose uptake in adipocytes.
abstract: Type 2 diabetes mellitus is characterized by disruption in glycemic homeostasis, involving impaired insulin-induced glucose disposal. For that, reduced glucose transporter GLUT4, encoded by Slc2a4 gene, plays a fundamental role. Conversely, increase in Slc2a4/GLUT4 expression improves glycemic homeostasis. Recent studies have proposed that estradiol is able to modulate Slc2a4 expression, according to distinct effects upon estrogen receptors ESR1/ESR2. We hypothesize that ESR1-agonist effect could stimulate Slc2a4 expression; thus, increasing cellular glucose disposal, which could be beneficial to glycemic control. Differentiated 3T3-L1 adipocytes were treated (24 hours) with selective ESR1- agonist PPT 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole, selective ESR1-antagonist MPP 1,3-Bis(4- hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride, and selective ESR2 agonist DPN 2,3-bis(4-Hydroxyphenyl)-propionitrile, with/without 17β-estradiol (E2). We analyzed Slc2a4 mRNA (real time PCR) and GLUT4 protein (Western blotting) expression, transcriptional activity of the Slc2a4 repressor Nuclear Factor- κB (NF-κB) (electrophoretic mobility shift assay), and cellular glucose disposal (2-deoxi-D-[(3)H]glucose uptake, 2-DG). ESR1-agonist PPT enhanced Slc2a4/GLUT4 expression (~30%) in the absence or presence of 0.1 and 10 nmol/L E2, and decreased the NF-κB binding activity (~50%). Conversely, ESR1-antagonist MPP, together with E2, decreased Slc2a4/GLUT4 expression (20-40%) and increased NF-κB binding activity (~30%). Furthermore, treatment with ESR2- agonist DPN decreased Slc2a4/GLUT4 expression (20-50%). 2-DG uptake was modulated in parallel to that observed in GLUT4 protein. The present results reveal that ESR1 activity enhances, whereas ESR2 activity represses, Slc2a4/GLUT4 expression. These effects are partially mediated by NF-κB, and allow parallel changes in adipocyte glucose disposal. Furthermore, the data provide evidences that ESR1-agonist PPT, as a Slc2a4/GLUT4 enhancer, can be a promising coadjuvant drug for diabetes mellitus therapy.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: R S
authors.initials: RS
authors.lastname: Campello
authors.forename: A B
authors.initials: AB
authors.lastname: Alves-Wagner
authors.forename: T F
authors.initials: TF
authors.lastname: Lucas
authors.forename: R C
authors.initials: RC
authors.lastname: Mori
authors.forename: D T
authors.initials: DT
authors.lastname: Furuya
authors.forename: C S
authors.initials: CS
authors.lastname: Porto
authors.forename: U F
authors.initials: UF
authors.lastname: Machado
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D047628:Estrogen Receptor alpha / Q000819:agonists*; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000235:genetics*; D007328:Insulin / Q000494:pharmacology*; D051379:Mice; D010636:Phenols / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011720:Pyrazoles / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D017931:DNA Primers; D047628:Estrogen Receptor alpha; D051275:Glucose Transporter Type 4; D007328:Insulin; D010636:Phenols; D011720:Pyrazoles; D012333:RNA, Messenger; C495693:Slc2a4 protein, mouse; C486184:4,4',4''-(4-propyl-((1)H)-pyrazole-1,3,5-triyl) tris-phenol; D005947:Glucose