title: Functional expression of thyrotropin receptor in differentiated 3T3-L1 cells: a possible model cell line of extrathyroidal expression of thyrotropin receptor.
abstract: Thyrotropin receptor (TSHR) in extrathyroidal tissue, especially fat tissue, is supposed to have important roles in the development of extrathyroidal manifestations of Graves' disease. However, the molecular mechanism of TSHR expression is not known. Expression of TSHR mRNA and TSH-dependent cAMP production were observed in differentiated but not in undifferentiated 3T3-L1 cells. Maximal expression was obtained when the cells were differentiated in the presence of insulin, dexamethasone, and isobutylmethylxanthine (IBMX). Dexamethasone and IBMX were indispensable for the first three days. On the other hand, after day 4, insulin was indispensable for the expression of TSHR. 3T3-L1 cell is the first non-thyroidal cell line reported that expresses TSHR and whose expression can be induced. 3T3-L1 cell can be a good model to investigate the mechanism of expression of TSHR and extrathyroidal manifestations of Graves' disease.
authors.affiliation: Third Department of Internal Medicine, University of Yamanashi Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Haraguchi
authors.forename: H
authors.initials: H
authors.lastname: Shimura
authors.forename: L
authors.initials: L
authors.lastname: Lin
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Endo
authors.forename: T
authors.initials: T
authors.lastname: Onaya
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D000242:Cyclic AMP / Q000378:metabolism; D017931:DNA Primers; D015342:DNA Probes; D003907:Dexamethasone / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism; D006111:Graves Disease; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis; D011989:Receptors, Thyrotropin / Q000096:biosynthesis*; D013961:Thyroid Gland / Q000378:metabolism; D013972:Thyrotropin / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D015342:DNA Probes; D007328:Insulin; D012333:RNA, Messenger; D011989:Receptors, Thyrotropin; D003907:Dexamethasone; D013972:Thyrotropin; D000242:Cyclic AMP; D005990:Glycerol; D015056:1-Methyl-3-isobutylxanthine