title: Serotonin transporter (SERT) and translocator protein (TSPO) expression in the obese ob/ob mouse.
abstract: BACKGROUND
  An ever growing body of evidences is emerging concerning metabolism hormones, neurotransmitters or stress-related biomarkers as effective modulators of eating behavior and body weight in mammals. The present study sought at examining the density and affinity of two proteins related to neurotransmission and cell metabolism, the serotonin transporter SERT and the cholesterol import-benzodiazepine site TSPO (translocator protein), in a rodent leptin-lacking mutant, the obese ob/ob mouse. Binding studies were thus carried out in brain or peripheral tissues, blood platelets (SERT) and kidneys (TSPO), of ob/ob and WT mice supplied with a standard diet, using the selective radiochemical ligands [3H]-paroxetine and [3H]-PK11195.
  
  
  RESULTS
  We observed comparable SERT number or affinity in brain and platelets of ob/ob and WT mice, whilst a significantly higher [3H]-PK11195 density was reported in the brain of ob/ob animals. TSPO binding parameters were similar in the kidneys of all tested mice. By [3H]-PK11195 autoradiography of coronal hypothalamic-hippocampal sections, an increased TSPO signal was detected in the dentate gyrus (hippocampus) and choroids plexus of ob/ob mice, without appreciable changes in the cortex or hypothalamic-thalamic regions.
  
  
  CONCLUSIONS
  These findings show that TSPO expression is up-regulated in cerebral regions of ob/ob leptin-deficient mice, suggesting a role of the translocator protein in leptin-dependent CNS trophism and metabolism. Unchanged SERT in mutant mice is discussed herein in the context of previous literature as the forerunner to a deeper biochemical investigation.
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy. ggino@farm.unipi.it
authors.forename: Gino
authors.initials: G
authors.lastname: Giannaccini
authors.forename: Laura
authors.initials: L
authors.lastname: Betti
authors.forename: Lionella
authors.initials: L
authors.lastname: Palego
authors.forename: Andrea
authors.initials: A
authors.lastname: Pirone
authors.forename: Lara
authors.initials: L
authors.lastname: Schmid
authors.forename: Mario
authors.initials: M
authors.lastname: Lanza
authors.forename: Laura
authors.initials: L
authors.lastname: Fabbrini
authors.forename: Caterina
authors.initials: C
authors.lastname: Pelosini
authors.forename: Margherita
authors.initials: M
authors.lastname: Maffei
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Santini
authors.forename: Aldo
authors.initials: A
authors.lastname: Pinchera
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D020738:Leptin / Q000172:deficiency; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D017374:Paroxetine / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D018079:Receptors, GABA / Q000096:biosynthesis*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000096:biosynthesis*
chemical_list: C463819:Bzrp protein, mouse; D020738:Leptin; D018079:Receptors, GABA; D050486:Serotonin Plasma Membrane Transport Proteins; C493231:Slc6a4 protein, mouse; D017374:Paroxetine