Exosomes Expressing Thyrotropin Receptor Attenuate Autoantibody-Mediated Stimulation of Cyclic Adenosine Monophosphate Production

Thyroid ◽  
2019 ◽  
Vol 29 (7) ◽  
pp. 1012-1017
Author(s):  
Naoki Edo ◽  
Kyojiro Kawakami ◽  
Yasunori Fujita ◽  
Koji Morita ◽  
Kenji Uno ◽  
...  
1988 ◽  
Vol 167 (6) ◽  
pp. 1963-1968 ◽  
Author(s):  
L S Gray ◽  
J Gnarra ◽  
E L Hewlett ◽  
V H Engelhard

Cholera toxin (CT), but not pertussis toxin (PT), treatment of cloned murine CTL inhibited target cell lysis in a dose-dependent fashion. The effects of CT were mimicked by forskolin and cyclic adenosine monophosphate (cAMP) analogues. Inhibition of cytotoxicity by CT and cAMP analogs was mediated in part by attenuation of conjugate formation. Additionally, both CT and cAMP analogs blocked the increase in intracellular Ca2+ induced by stimulation of the TCR complex by mAbs. These findings indicate that cAMP inhibits the activity of CTL by two distinct mechanisms and suggests a role for this second messenger in CTL-mediated cytolysis.


Science ◽  
1973 ◽  
Vol 179 (4073) ◽  
pp. 585-588 ◽  
Author(s):  
G. R. Siggins ◽  
E. F. Battenberg ◽  
B. J. Hoffer ◽  
F. E. Bloom ◽  
A. L. Steiner

1994 ◽  
Vol 130 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Ulla Björkman ◽  
Ragnar Ekholm

Björkman U, Ekholm R. Effect of P1-purinergic agonist on thyrotropin stimulation of H2O2 generation in FRTL-5 and porcine thyroid cells. Eur J Endocrinol 1994;130:180–6. ISSN 0804–4643 Our previous studies have shown that the generation of H2O2 in FRTL-5 thyroid cells is regulated via both the adenylate cyclase/cyclic adenosine monophosphate (cAMP) and Ca2+/phosphatidylinositol pathway: thyrotropin (TSH) stimulates H2O2 generation through both pathways, via the former at a low concentration and via the latter at a high concentration. In porcine thyrocytes in primary culture H2O2 generation is stimulated only via the Ca2+/phosphatidylinositol route. In the present study we explored the effect of a P1-purinergic agonist (phenylisopropyladenosine, PIA) on stimulations induced by TSH and by adenosine triphosphate (ATP), an activator of the Ca2+/phosphatidylinositol cascade via the P2-purinergic receptor. In FRTL- 5 cells, PIA potentiated H2O2 generation stimulated by TSH at 10U/l (but not at 1 U/l), Ca2+ mobilization induced by TSH and Ca2+ mobilization induced by ATP at 1 μmol/l (but not 10 μmol/l). Phenylisopropyladenosine strongly inhibited TSH-induced cAMP accumulation in FRTL-5 cells. In pig thyrocytes, PIA had no effect on H2O2 generation stimulated by TSH or ATP and no effect on ATP-stimulated Ca2+ mobilization. Also, PIA did not inhibit TSH-stimulated cAMP accumulation in pig thyrocytes, and by itselfhad no effecton H2O2 generation or Ca2 + mobilization. Thus, in FRTL-5 cells, but not in porcine thyrocytes, PIA modulates TSH-stimulated H2O2 generation by enhancing the Ca2+/phosphatitylinositol route and inhibiting the adenylate cyclase/cAMP route of the TSH signal. The net result of this modulation apparently depends on the balance between inhibition of the cAMP route and enhancement of the Ca2+ route. This may explain the lack of potentiation observed by 1 U/1 TSH. Ragnar Ekholm, Department of Anatomy, Medicinaregatan 3, S-413 90 Göteborg, Sweden


Sign in / Sign up

Export Citation Format

Share Document