title: Involvement of the ceramide signaling pathway in modulating the differentiated state of porcine thyroid cells.
abstract: Neutral sphingomyelinase (Smase) is a cell membrane-associated phospholipase that hydrolyzes sphingomyelin to phosphocholine and ceramide, a lipid second messenger involved in cell differentiation and/or apoptosis. We first evidenced that porcine cultured thyroid cells could express neutral Smase activity even if thyrotropin (TStH), an essential hormone in thyroid cell differentiation, was found to induce a 1.7-fold decrease in Smase activity. Triggering the ceramide pathway by exogenous addition of neutral bacterial Smase (0.1 U/mL for 48 h), which transiently increased ceramide level by fourfold, drastically modified thyroid cell morphology. The follicle-like structures generated by TSH were disrupted, and the Smase-induced cell spreading was accompanied by a parallel loss of cell ability to iodinate proteins as well as a decrease of the adenylate cyclase system response. These inhibitory effects have been reproduced using short-chain exogenous ceramide analogs (C2-ceramides). Overall these data showed that ceramides emerged as potential mediators of dedifferentiation in thyroid cells.
authors.affiliation: Université de Reims Champagne-Ardenne, UFR de Médecine et de Sciences, Reims, France.
authors.forename: C
authors.initials: C
authors.lastname: Schneider
authors.forename: N
authors.initials: N
authors.lastname: Delorme
authors.forename: N
authors.initials: N
authors.lastname: Buisson-Legendre
authors.forename: G
authors.initials: G
authors.lastname: Bellon
authors.forename: H
authors.initials: H
authors.lastname: Emonard
authors.forename: H E
authors.initials: HE
authors.lastname: Btaouri
authors.forename: W
authors.initials: W
authors.lastname: Hornebeck
authors.forename: B
authors.initials: B
authors.lastname: Haye
authors.forename: L
authors.initials: L
authors.lastname: Martiny
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism*; D015398:Signal Transduction; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism / Q000494:pharmacology; D013552:Swine; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology
chemical_list: D002518:Ceramides; D013972:Thyrotropin; D013108:Sphingomyelin Phosphodiesterase