Estradiol-induced regulation of GLUT4 in 3T3-L1 cells: involvement of ESR1 and AKT activation

Author(s)

Campello, Raquel S. ^[1] ; Fatima, Luciana A. ^[1] ; Barreto-Andrade, Joao Nilton ^[1] ; Lucas, Thais F. ^[2] ; Mori, Rosana C. ^[1] ; Porto, Catarina S. ^[2] ; Machado, Ubiratan F. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dep Physiol & Biophys, Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo, Escola Paulista Med, Dept Pharmacol, Sect Expt Endocrinol, Sao Paulo - Brazil

• Document type: Journal article
• Source: JOURNAL OF MOLECULAR ENDOCRINOLOGY; v. 59, n. 3, p. 257-268, OCT 2017.
• Web of Science Citations: 4

Abstract

Impaired insulin-stimulated glucose uptake involves reduced expression of the GLUT4 (solute carrier family 2 facilitated glucose transporter member 4, SLC2A4 gene). 17 beta-estradiol (E-2) modulates SLC2A4/GLUT4 expression, but the involved mechanisms are unclear. Although E-2 exerts biological effects by binding to estrogen receptors 1/2 (ESR1/2), which are nuclear transcriptional factors; extranuclear effects have also been proposed. We hypothesize that E-2 regulates GLUT4 through an extranuclear ESR1 mechanism. Thus, we investigated the effects of E-2 upon (1) subcellular distribution of ESRs and the proto-oncogene tyrosine-protein kinases (SRC) involvement; (2) serine/ threonine-protein kinase (AKT) activation; (3) Slc2a4/GLUT4 expression and (4) GLUT4 subcellular distribution and glucose uptake in 3T3-L1 adipocytes. Differentiated 3T3-L1 adipocytes were cultivated or not with E-2 for 24 h, and additionally treated or not with ESR1-selective agonist (PPT), ESR1-selective antagonist (MPP) or selective SRC inhibitor (PP2). Subcellular distribution of ESR1, ESR2 and GLUT4 was analyzed by immunocytochemistry; Slc2a4 mRNA and GLUT4 were quantified by qPCR and Western blotting, respectively; plasma membrane GLUT4 translocation and glucose uptake were analyzed under insulin stimulus for 20 min or not. E-2 induced (1) translocation of ESR1, but not of ESR2, from nucleus to plasma membrane and AKT phosphorylation, effects mimicked by PPT and blocked by MPP and PP2; (2) increased Slc2a4/GLUT4 expression and (3) increased insulin-stimulated GLUT4 translocation and glucose uptake. In conclusion, E-2 treatment promoted a SRC-mediated nucleus-plasma membrane shuttle of ESR1, and increased AKT phosphorylation, Slc2a4/GLUT4 expression and plasma membrane GLUT4 translocation; consequently, improving insulin-stimulated glucose uptake. These results unravel mechanisms through which estrogen improves insulin sensitivity. (AU)

• FAPESP's process: 12/04831-1 - New players in glycemic control and chronic complications of Diabetes mellitus: preventive and therapeutic perspectives
• Grantee: Ubiratan Fabres Machado
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/24210-1 - REGULATION OF Slc2a4/GLUT4 EXPRESSION BY 17²-ESTRADIOL
• Grantee: Raquel Saldanha Campello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral