title: Expression of insulin receptor substrates 1-3, glucose transporters GLUT-1-4, signal regulatory protein 1alpha, phosphatidylinositol 3-kinase and protein kinase B at the protein level in the human testis.
abstract: Insulin receptor substrates (IRS) mediate the biological actions of insulin, growth factors and cytokines. This action is via receptor-mediated tyrosine phosphorylation of IRS proteins. The aim of present study was to demonstrate the distribution of IRS-1-3, the glucose transporter class I subfamily (GLUT-1-4), signal regulatory protein 1alpha (SIRP1alpha), protein kinase B (PKB) and phosphatidylinositol kinase (PI3-K) in the human testis to determine whether signal transduction mediated by these proteins is active in testicular cells. In the present study, the expression of IRS-1-3, GLUT-1-4, SIRP1alpha, P13-K and PKB was studied in the human testis at the protein level using immunohistochemistry and western blotting. A positive immunoreaction for IRS-1 was found in the human testis in peritubular myoid cells and macrophage-like interstitial cells. A positive immunoreaction for GLUT-3 was found in the human testis in Sertoli cells, peritubular myoid cells, early spermatocytes, macrophage-like interstitial cells and cells in the small vessels walls. Western blotting demonstrated IRS-1, IRS-2 and GLUT-3 proteins in the human testis. Expression of IRS-3, GLUT-1, GLUT-2, GLUT-4, SIRP1alpha, P13-K and PKB was not detected in the human testis. The results of the present study suggest that proteins like insulin and certain cytokines using IRS-1, IRS-2 and GLUT-3 in their signal transduction pathways can have effects on different cell types of the testis in humans.
authors.affiliation: Department of Anatomy, University of Tartu, Estonia. kersti.kokk@ut.ee
authors.forename: Kersti
authors.initials: K
authors.lastname: Kokk
authors.forename: Esko
authors.initials: E
authors.lastname: Veräjänkorva
authors.forename: Matti
authors.initials: M
authors.lastname: Laato
authors.forename: Xiao-Ke
authors.initials: XK
authors.lastname: Wu
authors.forename: Helle
authors.initials: H
authors.lastname: Tapfer
authors.forename: Pasi
authors.initials: P
authors.lastname: Pöllänen
mesh_terms: D000943:Antigens, Differentiation / Q000032:analysis*; D004847:Epithelial Cells / Q000378:metabolism; D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D006801:Humans; D007150:Immunohistochemistry; D055504:Insulin Receptor Substrate Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D009004:Monosaccharide Transport Proteins / Q000032:analysis / Q000096:biosynthesis*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D019869:Phosphatidylinositol 3-Kinases / Q000032:analysis*; D010750:Phosphoproteins / Q000032:analysis / Q000096:biosynthesis*; D017346:Protein Serine-Threonine Kinases / Q000032:analysis*; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D051057:Proto-Oncogene Proteins c-akt; D011971:Receptors, Immunologic / Q000032:analysis*; D012708:Sertoli Cells / Q000166:cytology / Q000378:metabolism; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation; D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D055504:Insulin Receptor Substrate Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D009419:Nerve Tissue Proteins; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011971:Receptors, Immunologic; C526292:IRS1 protein, human; C526297:IRS2 protein, human; C491585:IRS3P protein, human; C495677:SLC2A1 protein, human; C495687:SLC2A3 protein, human