Leptin-sensitive neurons in mouse preoptic area express alpha 1A- and alpha 2A-adrenergic receptor isoforms.
Leptin binding to its functional receptor stimulates the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signalling pathway, finally resulting in nuclear translocation of the phosphorylated STAT3 (P-STAT3). Systemic treatment with leptin (3mg/kg; intraperitoneal injection) induced the appearance of P-STAT3-immunoreactive cells in adult mouse preoptic area (POA). Here we show that the vast majority of leptin-responsive cells were located in medial POA (mPOA), followed by the median preoptic nucleus. Rare, scattered and weakly stained cells were found in ventromedial preoptic nucleus and lateral preoptic area. Co-localization studies disclosed that mPOA leptin-responsive cells were neurons, and that a large proportion expressed the alpha(1A)- and/or alpha(2A)-adrenergic receptor (AR) isoforms. Although understanding the functional relevance of leptin-responsive POA neurons requires further investigation, the finding that they bear alpha-ARs suggests that they may be targeted by the ascending noradrenergic system, which densely innervates the mPOA, and thus be involved in thermoregulation, arousal and/or the sleep-wake cycle.
Frontini
Andrea
A
Department of Molecular Pathology and Innovative Therapies, School of Medicine, Marche Polytechnic University, Via Tronto 10/A, 60020 Ancona, Italy.
Giordano
Antonio
A
D000818:Animals; D020738:Leptin / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011301:Preoptic Area / Q000187:drug effects / Q000378:metabolism*; D020033:Protein Isoforms / Q000096:biosynthesis; D018340:Receptors, Adrenergic, alpha-1 / Q000096:biosynthesis*; D018341:Receptors, Adrenergic, alpha-2 / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000494:pharmacology; D050796:STAT3 Transcription Factor / Q000378:metabolism
C547714:Adra1a protein, mouse; C547769:Adra2a protein, mouse; D020738:Leptin; D020033:Protein Isoforms; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2; D011994:Recombinant Proteins; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse