Influence of transforming growth factor beta1 (TGF-beta1) on the behaviour of porcine thyroid epithelial cells in primary culture through thrombospondin-1 synthesis.
Transforming growth factor beta1 (TGF-beta1) is a secreted polypeptide that is thought to play a major role in the regulation of folliculogenesis and differentiation of thyroid cells. On porcine thyroid follicular cells cultured on plastic substratum, TGF-beta1, in a concentration-dependent way, promoted the disruption of follicles, cell spreading, migration and confluency by a mechanism that did not involve cell proliferation. TGF-beta1 strongly activated the production of thrombospondin-1 and (alpha)vbeta3 integrin in a concentration-dependent manner whereas the expression of thyroglobulin was unaffected. Anisomycin, an inhibitor of protein synthesis, inhibited the effect of TGF-beta1 on cell organization. Thrombospondin-1 reproduced the effect of TGF-beta1. In the presence of thrombospondin-1 cells did not organize in follicle-like structures but, in contrast, spreaded and reached confluency independently of cell proliferation. This effect is suppressed by an RGD-containing peptide. The adhesive properties of thrombospondin-1 for thyroid cells were shown to be mediated by both the amino-terminal heparin-binding domain and the RGD domain of thrombospondin-1. Adhesion was shown to involve (alpha)vbeta3 integrin. The results show that TGF-beta1 exerted an influence upon function and behaviour of follicle cells partly mediated by the synthesis of thrombospondin-1 and of its receptor (alpha)vbeta3 integrin.
Claisse
D
D
Laboratoire de Biochimie, UPRES-A CNRS 6021, IFR 53-Biomolécules, Faculté Des Sciences, Moulin de la Housse, BP 1039, France.
Martiny
I
I
Chaqour
B
B
Wegrowski
Y
Y
Petitfrere
E
E
Schneider
C
C
Haye
B
B
Bellon
G
G
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D019030:Receptors, Vitronectin / Q000502:physiology; D013552:Swine; D019700:Thrombospondin 1 / Q000096:biosynthesis*; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013972:Thyrotropin / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D019030:Receptors, Vitronectin; D019700:Thrombospondin 1; D016212:Transforming Growth Factor beta; D013972:Thyrotropin