title: Desensitisation of native and recombinant human urotensin-II receptors.
abstract: Human urotensin-II (U-II) is an 11-amino-acid cyclic peptide that activates a G(q)-coupled receptor named UT. Little is known about the desensitisation profile of this receptor as peptide binding is essentially irreversible. In the present study, we have examined the effects of U-II and carbachol on Ca(2+) signalling in SJCRH30 rhabdomyosarcoma (receptor density, B(max) approximately 0.1 pmol/mg protein) and human embroynic kidney (HEK)(hUT) (B(max) approximately 1.4 pmol/mg protein) cells expressing native and recombinant UT, respectively. In SJCRH30, HEK(hUT) and human peripheral blood mononuclear cells induced to express native UT by treatment with 2 microg/ml lipopolysaccharide (LPS), we have measured the effects of U-II treatment on UT mRNA. In SJCRH30 cells, primary stimulation with carbachol (250 microM) did not affect a secondary challenge with U-II (1 microM) and primary challenge with U-II did not affect a secondary challenge with carbachol. In contrast, in HEK(hUT) cells, primary stimulation with carbachol (250 microM) reduced a secondary challenge to U-II (1 microM) by 84% and primary challenge with U-II reduced a secondary challenge to carbachol by 76%. Pre-treatment of SJCRH30 cells with U-II reduced UT mRNA after 6 h and this returned to basal after 24 h. In recombinant HEK(hUT) cells, UT mRNA expression increased following a 6 h treatment with 1 microM U-II. U-II treatment of naïve un-stimulated peripheral blood mononuclear cells was without effect. However, when UT expression is up-regulated following 15 h of LPS treatment, a 6 h U-II challenge reduced UT mRNA by 66%. In summary, we report differences in the desensitisation profiles of native and recombinant U-II receptors. Design and interpretation of functional experiments are hampered by irreversibility of U-II binding.
authors.affiliation: Division of Anaesthesia, Critical Care and Pain Management, University Department of Cardiovascular Sciences (Pharmacology and Therapeutics Group), University of Leicester, Leicester, LE1 5WW, UK.
authors.forename: Madura S
authors.initials: MS
authors.lastname: Batuwangala
authors.forename: Girolamo
authors.initials: G
authors.lastname: Calo
authors.forename: Remo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Leong L
authors.initials: LL
authors.lastname: Ng
authors.forename: John
authors.initials: J
authors.lastname: McDonald
authors.forename: David G
authors.initials: DG
authors.lastname: Lambert
mesh_terms: D000328:Adult; D020013:Calcium Signaling / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology*; D002460:Cell Line; D045744:Cell Line, Tumor; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008070:Lipopolysaccharides; D008875:Middle Aged; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012208:Rhabdomyosarcoma / Q000378:metabolism; D014579:Urotensins / Q000494:pharmacology*
chemical_list: D008070:Lipopolysaccharides; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; C121697:UTS2R protein, human; D014579:Urotensins; D002217:Carbachol; C029677:urotensin II
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 2004 Mar;369(3):271-3
references.pmid: 14985940
references.citation: Methods Mol Biol. 2006;312:37-45
references.pmid: 16422189
references.citation: J Cardiovasc Pharmacol. 2000 Nov;36(5 Suppl 1):S163-6
references.pmid: 11078367
references.citation: Oncogene. 1999 Nov 22;18(49):6853-66
references.pmid: 10602461
references.citation: J Neurochem. 2002 Nov;83(4):879-84
references.pmid: 12421360
references.citation: Cardiovasc Hematol Agents Med Chem. 2008 Apr;6(2):80-91
references.pmid: 18473773
references.citation: Peptides. 2008 May;29(5):721-6
references.pmid: 18314227
references.citation: J Biol Chem. 1985 Mar 25;260(6):3440-50
references.pmid: 3838314
references.citation: Peptides. 2008 May;29(5):658-73
references.pmid: 17931747
references.citation: Anesth Analg. 2007 Oct;105(4):998-1005, table of contents
references.pmid: 17898379
references.citation: Nature. 1999 Sep 16;401(6750):282-6
references.pmid: 10499587
references.citation: Br J Pharmacol. 2004 Jul;142(6):921-32
references.pmid: 15210573
references.citation: Cell Signal. 1999 Oct;11(10):743-51
references.pmid: 10574329
references.citation: Eur J Pharmacol. 2001 Jul 6;423(2-3):121-5
references.pmid: 11448475
references.citation: Eur J Pharmacol. 2008 Sep 28;593(1-3):24-9
references.pmid: 18671962
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 2007 Oct;376(1-2):107-15
references.pmid: 17701026
references.citation: Br J Pharmacol. 2003 Sep;140(1):61-70
references.pmid: 12967935
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 2002 Feb;365(2):141-9
references.pmid: 11819032
references.citation: J Endocrinol. 1969 Sep;45(1):Suppl:xi-xii
references.pmid: 5347394
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 2007 Nov;376(3):217-25
references.pmid: 17899014
references.citation: Trends Pharmacol Sci. 2004 Feb;25(2):76-85
references.pmid: 15102493
references.citation: Trends Endocrinol Metab. 2004 May-Jun;15(4):175-82
references.pmid: 15109617
references.citation: J Immunol. 2007 Jul 15;179(2):901-9
references.pmid: 17617581
references.citation: Peptides. 2008 May;29(5):680-90
references.pmid: 18022732
references.citation: Anesth Analg. 2008 Mar;106(3):865-6, table of contents
references.pmid: 18292431
references.citation: J Anesth. 2007;21(3):378-89
references.pmid: 17680191
references.citation: Growth Factors. 2009 Jun;27(3):155-62
references.pmid: 19326266
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 2006 May;373(2):148-57
references.pmid: 16596397
references.citation: Br J Pharmacol. 2001 Sep;134(2):257-64
references.pmid: 11564643
references.citation: Physiol Rev. 2008 Apr;88(2):421-49
references.pmid: 18391169
references.citation: Mol Pharmacol. 2004 Jun;65(6):1507-16
references.pmid: 15155843
references.citation: Anal Biochem. 1987 Apr;162(1):156-9
references.pmid: 2440339