title: Acute inflammation increases pituitary and hypothalamic glycoprotein hormone subunit B5 mRNA expression in association with decreased thyrotrophin receptor mRNA expression in mice.
abstract: The biological function of thyrostimulin, consisting of the GPA2 and GPB5 subunit, is currently poorly understood. The recent observation that pro-inflammatory cytokines up-regulate the transcription of GPB5 in vitro suggested a role for thyrostimulin in the nonthyroidal illness syndrome, a state of altered thyroid hormone metabolism occurring during illness. In the present study, we used GPB5 knockout (GPB5(-/-) ) and wild-type (WT) mice to evaluate the role of GPB5 in the pituitary and hypothalamus during acute inflammation induced by lipopolysaccharide (LPS, bacterial endotoxin) administration. We evaluated serum thyroid hormones and mRNA expression of genes involved in thyroid hormone metabolism in the pituitary and in two hypothalamic regions; the periventricular region (PE) and the arcuate nucleus/median eminence region. As expected, LPS administration increased deiodinase type 2 mRNA in the PE, at the same time as decreasing pituitary thyrotrophin (TSH)β mRNA and serum thyroxine and triiodothyronine both in GPB5(-/-) and WT mice. GPB5 mRNA, but not GPA2 mRNA, markedly increased after LPS in the pituitary (200-fold) and hypothalamus of WT mice. In addition, we found large (>50%) suppression of TSH receptor (TSHR) mRNA in the pituitary and hypothalamus of WT mice but not in GPB5(-/-) mice. In conclusion, our results demonstrate in vivo regulation of central GPB5 transcription during acute illness. The observed differences between GPB5(-/-) and WT mice point to a distinct role for GPB5 in pituitary and hypothalamic TSHR suppression during acute illness.
authors.affiliation: Department of Endocrinology & Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. c.j.vanzeijl@amc.uva.nl
authors.forename: C J J
authors.initials: CJ
authors.lastname: van Zeijl
authors.forename: O V
authors.initials: OV
authors.lastname: Surovtseva
authors.forename: W M
authors.initials: WM
authors.lastname: Wiersinga
authors.forename: E
authors.initials: E
authors.lastname: Fliers
authors.forename: A
authors.initials: A
authors.lastname: Boelen
mesh_terms: D000818:Animals; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D007031:Hypothalamus / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism*; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D007453:Iodide Peroxidase / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D036361:Peptide Hormones / Q000235:genetics / Q000378:metabolism*; D010902:Pituitary Gland / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011989:Receptors, Thyrotropin / Q000235:genetics* / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: C559612:GPB5 protein, mouse; D006023:Glycoproteins; D053583:Interleukin-1beta; D007527:Isoenzymes; D008070:Lipopolysaccharides; D036361:Peptide Hormones; D011498:Protein Precursors; D021122:Protein Subunits; D012333:RNA, Messenger; D011989:Receptors, Thyrotropin; C458339:thyrostimulin; D014284:Triiodothyronine; D007453:Iodide Peroxidase; D013974:Thyroxine