title: Autoantibodies against muscarinic type 3 receptor in Sjögren's syndrome inhibit aquaporin 5 trafficking.
abstract: Sjögren's syndrome (SjS) is a chronic autoimmune disease that mainly targets the salivary and lacrimal glands. It has been controversial whether anti-muscarinic type 3 receptor (α-M3R) autoantibodies in patients with SjS inhibit intracellular trafficking of aquaporin-5 (AQP5), water transport protein, leading to secretory dysfunction. To address this issue, GFP-tagged human AQP5 was overexpressed in human salivary gland cells (HSG-hAQP5) and monitored AQP5 trafficking to the plasma membrane following carbachol (CCh, M3R agonist) stimulation. AQP5 trafficking was indeed mediated by M3R stimulation, shown in partial blockage of trafficking by M3R-antagonist 4-DAMP. HSG-hAQP5 pre-incubated with SjS plasma for 24 hours significantly reduced AQP5 trafficking with CCh, compared with HSG-hAQP5 pre-incubated with healthy control (HC) plasma. This inhibition was confirmed by monoclonal α-M3R antibody and pre-absorbed plasma. Interestingly, HSG-hAQP5 pre-incubated with SjS plasma showed no change in cell volume, compared to the cells incubated with HC plasma showing shrinkage by twenty percent after CCh-stimulation. Our findings clearly indicate that binding of anti-M3R autoantibodies to the receptor, which was verified by immunoprecipitation, suppresses AQP5 trafficking to the membrane and contribute to impaired fluid secretion in SjS. Our current study urges further investigations of clinical associations between SjS symptoms, such as degree of secretory dysfunction, cognitive impairment, and/or bladder irritation, and different profiles (titers, isotypes, and/or specificity) of anti-M3R autoantibodies in individuals with SjS.
authors: Department of Oral and Maxillofacial Diagnostic Sciences, University of Florida College of Dentistry, Gainesville, Florida, United States of America.
authors: Byung Ha
authors: BH
authors: Lee
authors: Adrienne E
authors: AE
authors: Gauna
authors: Geidys
authors: G
authors: Perez
authors: Yun-jong
authors: YJ
authors: Park
authors: Kaleb M
authors: KM
authors: Pauley
authors: Toshihisa
authors: T
authors: Kawai
authors: Seunghee
authors: S
authors: Cha
mesh_terms: D000328:Adult; D000368:Aged; D051402:Aquaporin 5 / Q000235:genetics / Q000378:metabolism*; D001323:Autoantibodies / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000166:cytology / Q000378:metabolism; D008875:Middle Aged; D021381:Protein Transport; D043587:Receptor, Muscarinic M3 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000276:immunology; D012469:Salivary Glands / Q000166:cytology / Q000378:metabolism*; D012859:Sjogren's Syndrome / Q000378:metabolism* / Q000473:pathology
chemical_list: C496036:AQP5 protein, human; D051402:Aquaporin 5; D001323:Autoantibodies; D043587:Receptor, Muscarinic M3; D002217:Carbachol; D002118:Calcium
references: Arch Immunol Ther Exp (Warsz). 2009 Jan-Feb;57(1):57-66
references: 19219532
references: Am J Physiol Cell Physiol. 2011 Sep;301(3):C667-78
references: 21633078
references: Eur J Pharmacol. 2003 Mar 19;464(2-3):197-206
references: 12620514
references: J Rheumatol. 2005 Jun;32(6):1071-5
references: 15940770
references: J Biol Chem. 2001 Jun 29;276(26):23413-20
references: 11290736
references: Arthritis Rheum. 2000 Jul;43(7):1647-54
references: 10902771
references: Curr Pharm Des. 2006;12(28):3573-81
references: 17073660
references: Curr Opin Rheumatol. 2009 Sep;21(5):465-70
references: 19568172
references: Lab Invest. 2001 Feb;81(2):143-8
references: 11232635
references: Arthritis Rheum. 2005 Oct;52(10):2984-95
references: 16200578
references: Prog Histochem Cytochem. 2004;39(1):1-83
references: 15242101
references: Cancer Lett. 2008 Oct 18;270(1):87-94
references: 18585854
references: J Autoimmun. 2005 Feb;24(1):47-54
references: 15725576
references: J Physiol. 2007 Jun 1;581(Pt 2):801-17
references: 17379640
references: Clin Exp Immunol. 2010 Oct;162(1):53-61
references: 20731676
references: Lab Invest. 2004 Nov;84(11):1430-8
references: 15448705
references: Mod Rheumatol. 2012 Apr;22(2):264-71
references: 21877253
references: Hum Immunol. 2005 Apr;66(4):411-6
references: 15866705
references: FEBS Lett. 2000 Jul 21;477(3):253-7
references: 10908730
references: Acta Physiol Hung. 2007 Dec;94(4):301-13
references: 18038758
references: Front Biosci. 2007 Jan 01;12:1767-89
references: 17127420
references: Respir Physiol Neurobiol. 2011 May 31;176(3):110-7
references: 21315850
references: Biochem Biophys Res Commun. 1999 Dec 20;266(2):443-7
references: 10600522
references: Tissue Eng. 2005 Sep-Oct;11(9-10):1449-58
references: 16259600
references: Arthritis Rheum. 2000 Oct;43(10):2297-306
references: 11037890
references: Pflugers Arch. 1994 Jun;427(3-4):203-9
references: 8072837
references: Arthritis Rheum. 2004 Aug;50(8):2615-21
references: 15334476
references: Scand J Immunol. 2004 Mar;59(3):261-6
references: 15030576
references: Lancet. 2005 Jul 23-29;366(9482):321-31
references: 16039337
references: Biochem Biophys Res Commun. 1998 Apr 28;245(3):835-40
references: 9588201
references: Am J Physiol Cell Physiol. 2005 Nov;289(5):C1303-11
references: 16107506
references: Ann Rheum Dis. 2002 Jun;61(6):554-8
references: 12006334
references: J Membr Biol. 1994 Nov;142(2):181-93
references: 7884810
references: Science. 1989 Jun 30;244(4912):1582-5
references: 2500708
references: Arthritis Rheum. 2007 Aug;56(8):2566-74
references: 17665453
references: J Biol Chem. 1999 Jul 16;274(29):20071-4
references: 10400615
references: J Cell Sci. 2005 Sep 15;118(Pt 18):4131-9
references: 16118245
references: Lancet. 2001 Dec 1;358(9296):1875-6
references: 11741631
references: Ann Rheum Dis. 2011 Jan;70(1):235-6
references: 20498204
references: J Rheumatol. 2006 Feb;33(2):296-306
references: 16465661
references: Lancet. 2001 Mar 3;357(9257):688-9
references: 11247557
references: Curr Eye Res. 2008 Aug;33(8):621-9
references: 18696337
references: Biochem Biophys Res Commun. 1999 Nov;265(1):94-100
references: 10548496