title: GIP-dependent expression of hypothalamic genes.
abstract: GIP (glucose dependent insulinotrophic polypeptide), originally identified as an incretin peptide synthesized in the gut, has recently been identified, along with its receptors (GIPR), in the brain. Our objective was to investigate the role of GIP in hypothalamic gene expression of biomarkers linked to regulating energy balance and feeding behavior related neurocircuitry. Rats with lateral cerebroventricular cannulas were administered 10 μg GIP or 10 microl artificial cerebrospinal fluid (aCSF) daily for 4 days, after which whole hypothalami were collected. Real time Taqman™ RT-PCR was used to quantitatively compare the mRNA expression levels of a set of genes in the hypothalamus. Administration of GIP resulted in up-regulation of hypothalamic mRNA levels of AVP (46.9±4.5 %), CART (25.9±2.7 %), CREB1 (38.5±4.5 %), GABRD (67.1±11 %), JAK2 (22.1±3.6 %), MAPK1 (33.8±7.8 %), NPY (25.3±5.3 %), OXT (49.1±5.1 %), STAT3 (21.6±3.8 %), and TH (33.9±8.5 %). In a second experiment the same set of genes was evaluated in GIPR(-/-) and GIPR(+/?) mice to determine the effect of lack of GIP stimulation on gene expression. In GIPR(-/-) mice expressions of the following genes were down-regulated: AVP (27.1±7.5 %), CART (28.3±3.7 %), OXT (25.2±5.8 %), PTGES (23.9±4.5 %), and STAT3 (8.8±2.3 %). These results suggest that AVP, CART, OXT and STAT3 may be involved in energy balance-related hypothalamic circuits affected by GIP.
authors: Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602-2771, USA.
authors: S
authors: S
authors: Ambati
authors: J
authors: J
authors: Duan
authors: D L
authors: DL
authors: Hartzell
authors: Y-H
authors: YH
authors: Choi
authors: M A
authors: MA
authors: Della-Fera
authors: C A
authors: CA
authors: Baile
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D004734:Energy Metabolism / Q000235:genetics; D005247:Feeding Behavior; D005749:Gastric Inhibitory Polypeptide / Q000494:pharmacology / Q000502:physiology*; D015870:Gene Expression; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011964:Receptors, Gastrointestinal Hormone / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D011964:Receptors, Gastrointestinal Hormone; D005749:Gastric Inhibitory Polypeptide; C041086:gastric inhibitory polypeptide receptor