title: Angiotensin II (AngII) induces the expression of suppressor of cytokine signaling (SOCS)-3 in rat hypothalamus - a mechanism for desensitization of AngII signaling.
abstract: Angiotensin II exerts a potent dypsogenic stimulus on the hypothalamus, which contributes to its centrally mediated participation in the control of water balance and blood pressure. Repetitive intracerebroventricular (i.c.v.) injections of angiotensin II lead to a loss of effect characterized as physiological desensitization to the peptide's action. In the present study, we demonstrate that angiotensin II induces the expression of suppressor of cytokine signaling (SOCS)-3 via angiotensin receptor 1 (AT1) and JAK-2, mostly located at the median preoptic lateral and anterodorsal preoptic nuclei. SOCS-3 produces an inhibitory effect upon the signal transduction pathways of several cytokines and hormones that employ members of the JAK/STAT families as intermediaries. The partial inhibition of SOCS-3 translation by antisense oligonucleotide was sufficient to significantly reduce the refractoriness of repetitive i.c.v. angiotensin II injections, as evaluated by water ingestion. Thus, by acting through AT1 on the hypothalamus, angiotensin II induces the expression of SOCS-3 which, in turn, blocks further activation of the pathway and consequently leads to desensitization to angiotensin II stimuli concerning its dypsogenic effect.
authors.affiliation: Department of Internal Medicine, University of Campinas, Campinas SP, Brazil.
authors.forename: Márcio A
authors.initials: MA
authors.lastname: Torsoni
authors.forename: José B
authors.initials: JB
authors.lastname: Carvalheira
authors.forename: Vivian C
authors.initials: VC
authors.lastname: Calegari
authors.forename: Rosangela M N
authors.initials: RM
authors.lastname: Bezerra
authors.forename: Mário J A
authors.initials: MJ
authors.lastname: Saad
authors.forename: José A
authors.initials: JA
authors.lastname: Gontijo
authors.forename: Lício A
authors.initials: LA
authors.lastname: Velloso
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D003864:Depression, Chemical; D004327:Drinking Behavior / Q000187:drug effects*; D007031:Hypothalamus / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D053614:Janus Kinase 2; D008297:Male; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D016376:Oligonucleotides, Antisense; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D012097:Repressor Proteins; C491410:Socs3 protein, rat; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D014157:Transcription Factors; D000804:Angiotensin II; D011505:Protein-Tyrosine Kinases; C507927:Jak2 protein, rat; D053614:Janus Kinase 2