Plasma from patients with seronegative myasthenia gravis inhibit nAChR responses in the TE671/RD cell line
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Abstract
Myasthenia gravis (MG) is an autoimmune disorder in which anti-acetylcholine receptor (AChR) antibodies cause muscle weakness. In 10–15% of MG patients anti-AChR antibodies are undetectable (seronegative MG, SMG), though clinical and experimental evidence points to causative circulating factors. Using whole-cell patch-clamp techniques, we investigated the effects of heat-inactivated plasma from SMG patients (n=7) on voltage-gated sodium [INa(V)] and ACh-induced nicotinic AChR (nAChR) currents in the human rhabdomyosarcoma cell line TE671/RD, comparing the results to those obtained with plasma from healthy individuals (HC, n=6), patients with Guillain-Barré syndrome (GBS, n=3) or those with other neurological diseases (OND, n=3). None of the plasma samples inhibited INa(V). nAChR currents were rapidly (<1 min) and significantly (P<0.01) reduced by a 1∶10 dilution of plasma from SMG patients compared with plasma from healthy controls and were not restored by washing. The inhibition appeared in some cases to be calcium dependent since for one of three plasmas it was prevented by 10 mM EGTA in the patch pipette. Currents were also reduced by two of three plasmas obtained from GBS patients at 1∶3 dilution, but not by the three plasmas from patients with ONDs. The rapid action of plasma from SMG patients argues against an antibodyinduced reduction in nAChR numbers; its calcium dependence in one case suggests action by a second messenger that might involve nAChR phosphorylation.
Key words
Seronegative myasthenia gravis Guillain-Barré syndrome Nicotinic acetylcholine receptor TE671/RD cell line Autoimmunity PhosphorylationPreview
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References
- 1.Barrett-Jolley RA, Byrne NG, Vincent A, Newsom-Davis J (1991) Effects of seronegative myasthenic plasma on the voltage gated sodium channel and the ACh activated cation channel of a whole-cell voltage clamped muscle cell line. J Autoimmun 4:2Google Scholar
- 2.Barrett-Jolley RA, Byrne NG, Vincent A, Newsom-Davis J (1992) Inhibition of ACh-currents by human plasma in a whole-cell voltage clamped human muscle cell line. J Physiol (Lond) 446:267PGoogle Scholar
- 3.Barrett-Jolley RA, Byrne NG, Newsom-Davis J, Vincent A (1992) Caffeine inhibition of ACh nicotinic currents in the human muscle (TE671) cell line not mediated by cyclic AMP/ Ca2+. J Physiol (Lond) 452:193PGoogle Scholar
- 4.Brinkmeir H, Wollinksy KH, Hülser P-J, Seewald MJ, Mehrkens H-H, Kornhuber HH, Rüdel R (1992) The acute paralysis in Guillain-Barré syndrome is related to a Na+ channel blocking factor in the cerebrospinal fluid. Pflügers Arch 421:552–557Google Scholar
- 5.Cockcroft S, Thomas GMH (1992) Inositol-lipid-specific phospholipase C isoenzymes and their differential regulation by receptors. Biochem J 288:1–14Google Scholar
- 6.Falker B, Ruppersberg JP, Spittelmeister W, Rüdel R (1990) Inactivation of human sodium channels and the effect of tocainide. Pflügers Arch 415:693–700Google Scholar
- 7.Gambale F, Montal M (1990) Voltage-gated sodium channels expressed in the human cerebellar medulloblastoma cell line TE671. Mol Brain Res 7:123–129Google Scholar
- 8.Grassi F, Monaco L, Eusebi F (1987) Acetylcholine receptor channel properties in rat myotubes exposed to forskolin. Biochem Biophys Res Commun 147:1000–1007Google Scholar
- 9.Grassi F, Giovannelli A, Fucile S, Mattei E, Eusebi F (1993) Cholinergic responses in cloned human TE671/RD tumour cells. Pflügers Arch 425:117–125Google Scholar
- 10.Giovannelli A, Farini D, Gauzzi MC, Alema S, Eusebi F (1990) Regulation of acetylcholine receptor desensitisation in mouse myotubes by cytosolic cyclic AMP. Cell Signal 2:347–352Google Scholar
- 11.Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ (1981) Improved patch-clamp technique for high-resolution current recordings from cells and cell-free membrane patches. Pflügers Arch 391:85–100Google Scholar
- 12.Huganir RL, Greengard P (1987) Regulation of receptor function by protein phosphorylation. Trends Pharmacol Sci 8:472–475Google Scholar
- 13.Huganir RL, Delcour AH, Greengard P, Hess GP (1986) Phosphorylation of the nicotinic acetylcholine receptor regulates its rate of desensitisation. Nature 321:774–776Google Scholar
- 14.Lang B, Richardson G, Rees J, Vincent A, Newsom-Davis J (1988) Plasma from myasthenia gravis patients reduces acetylcholine receptor agonist-induced Na+ flux into TE671. J Neuroimmunol 19:141–148Google Scholar
- 15.Laurenza A, McHugh-Sutkowski E, Seamon KB (1989) Forskolin: a specific stimulator of adenyl cyclase of a diterpene with multiple sites of action. Trends Pharmacol Sci 10:442–447Google Scholar
- 16.Luther MA, Schoepfer T, Whiting P, Casey B, Blatt Y, Montal MS, Montal M, Lindstrom J (1989) A muscle acetylcholine receptor is expressed in the human cerebellar medulloblastoma cell line TE671. J Neurosci 9:1082–1096Google Scholar
- 17.Middleton P, Fernán J, Schuetze SM (1986) Forskolin increases the rate of ACh-receptor desensitization at rat soleus endplates. Proc Natl Acad Sci USA 83:4967–4971Google Scholar
- 18.Mier AK, Havard CWH (1985) Diaphragmatic myasthenia in mother and child. Postgrad Med J 61:725–727Google Scholar
- 19.Mossman S, Vincent A, Newsom-Davis J (1986) Myasthenia gravis without acetylcholine receptor antibody: a distinct disease entitiy. Lancet i:116–119Google Scholar
- 20.Mulle C, Benoit P, Pinset C, Roa M, Changeux J-P (1988) Calcitonin gene-related peptide enhances the rate of desensitization of the nicotinic acetylcholine receptor in cultured mouse muscle cells. Proc Natl Acad Sci USA 85:5728–5732Google Scholar
- 21.Nishizuka Y (1988) The molecular heterogenity of protein kinase C and implications for cellular regulation. Nature 334:661–665Google Scholar
- 22.Pappone PA (1980) Voltage clamp experiments in normal and denervated mammalian skeletal muscle fibres. J Physiol (Lond) 306:377–410Google Scholar
- 23.Revah F, Mulle C, Pinset C, Audhya T, Goldstein G, Changeux J-P (1987) Calcium-dependent effect of the thymic polypeptide thymopoietin on the desensitization of the nicotinic acetylcholine receptor. Proc Natl Acad Sci USA 84:3477–3481Google Scholar
- 24.Siara J, Ruppersberg JP, Rüdel R (1990) Human nicotinic acetylcholine receptor: the influence of second messengers, on activation and desensitization. Pflügers Arch 415:701–706Google Scholar
- 25.Stratton MR, Darling J, Pilkington GJ, Lantos PL, Reeves BR, Cooper CS (1989) Characterization of the human cell line TE671. Carcinogenesis 10:899–905Google Scholar
- 26.Vincent A, Newsom-Davis J (1985) Acetylcholine receptor antibody as a diagnostic test for myasthenia gravis: 153 validated cases and 2967 diagnostic assays. J Neurol Neurosurg Psychiatry 47:1246–1252Google Scholar
- 27.Vincent A, Li Z, Hart A et al. (1993) Seronegative myasthenia gravis. Evidence for plasma factor(s) interfering with acetylcholine receptor function. Ann NY Acad Sci 681:529–538Google Scholar
- 28.Wagoner PK, Pallotta BS (1988) Modulation of ACh-receptor desensitisation by forskolin is independent of cAMP. Science 240:1655–1657Google Scholar
- 29.Willcox N, Vincent A (1988) Myasthenia gravis as an example of organ-specific autoimmune disease. In: Bird AG, Calvert JE (eds) The B lymphocyte in human disease. Oxford University Press, London, pp 496–506Google Scholar
- 30.Yamamoto T, Vincent A, Ciulla T, Lang B, Johnston I, Newsom-Davis J (1991) Seronegative myasthenia gravis: a plasma factor inhibiting agonist-induced acetylcholine receptor function copurifies with IgM. Ann Neurol 30:550–557Google Scholar