title: Rapid responses to reverse T₃ hormone in immature rat Sertoli cells: calcium uptake and exocytosis mediated by integrin.
abstract: There is increasing experimental evidence of the nongenomic action of thyroid hormones mediated by receptors located in the plasma membrane or inside cells. The aim of this work was to characterize the reverse T₃ (rT₃) action on calcium uptake and its involvement in immature rat Sertoli cell secretion. The results presented herein show that very low concentrations of rT₃ are able to increase calcium uptake after 1 min of exposure. The implication of T-type voltage-dependent calcium channels and chloride channels in the effect of rT₃ was evidenced using flunarizine and 9-anthracene, respectively. Also, the rT₃-induced calcium uptake was blocked in the presence of the RGD peptide (an inhibitor of integrin-ligand interactions). Therefore, our findings suggest that calcium uptake stimulated by rT₃ may be mediated by integrin αvβ₃. In addition, it was demonstrated that calcium uptake stimulated by rT₃ is PKC and ERK-dependent. Furthermore, the outcomes indicate that rT₃ also stimulates cellular secretion since the cells manifested a loss of fluorescence after 4 min incubation, indicating an exocytic quinacrine release that seems to be mediated by the integrin receptor. These findings indicate that rT₃ modulates the calcium entry and cellular secretion, which might play a role in the regulation of a plethora of intracellular processes involved in male reproductive physiology.
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis-Santa Catarina, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Zanatta
authors.forename: Leila
authors.initials: L
authors.lastname: Zanatta
authors.forename: Renata
authors.initials: R
authors.lastname: Gonçalves
authors.forename: Ariane
authors.initials: A
authors.lastname: Zamoner
authors.forename: Fátima Regina Mena Barreto
authors.initials: FR
authors.lastname: Silva
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects*; D016023:Integrins / Q000378:metabolism*; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012708:Sertoli Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D014285:Triiodothyronine, Reverse / Q000494:pharmacology*; D000090324:Tumor Protein, Translationally-Controlled 1
chemical_list: D015220:Calcium Channels; D018118:Chloride Channels; D016023:Integrins; C000715649:Tpt1 protein, rat; D000090324:Tumor Protein, Translationally-Controlled 1; D014285:Triiodothyronine, Reverse; D011493:Protein Kinase C; D020929:Mitogen-Activated Protein Kinase Kinases; D002118:Calcium