title: Triiodothyronine stimulates cystatin C production in bone cells.
abstract: Thyroid hormones increase cystatin C levels in vivo. To study whether 3,3',5-triiodo-l-thyronine (T(3)) stimulates the production of cystatin C in vitro, we used a T(3)-responsive osteoblastic cell line (PyMS) which can be kept in serum-free culture. We compared the effects of T(3) on cystatin C mRNA expression (by Northern) and on protein release (by Western and ELISA) with those of dexamethasone (dex). Triiodothyronine increased cystatin C mRNA expression and cystatin C accumulation in culture media in a dose- and time-dependent manner, 1.5-fold at 1 nmol/l after 4d; dex (100 nmol/l) was more potent and increased cystatin C accumulation 3-fold after 4d. Triiodothyronine but not dex stimulated glucose uptake. Our in vitro findings explain in vivo observations. Triiodothyronine-induced increase in the production of cystatin C may be related to an increased cell metabolism and proteolysis control demand.
authors.affiliation: Division of Endocrinology and Diabetology, University Hospital of Zurich, CH-8091 Zurich, Switzerland. christoph.schmid@usz.ch
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmid
authors.forename: Claudia
authors.initials: C
authors.lastname: Ghirlanda-Keller
authors.forename: Cornelia
authors.initials: C
authors.lastname: Zwimpfer
authors.forename: Evangelos
authors.initials: E
authors.lastname: Zoidis
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000818:Animals; D002478:Cells, Cultured; D055316:Cystatin C / Q000096:biosynthesis*; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D051274:Glucose Transporter Type 3 / Q000096:biosynthesis; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D055316:Cystatin C; D051274:Glucose Transporter Type 3; D012333:RNA, Messenger; D014284:Triiodothyronine; C060458:3-deoxyglucose; D003907:Dexamethasone; D003847:Deoxyglucose; D000469:Alkaline Phosphatase