1. Regulation of thymosin beta10 expression by TSH and other mitogenic signals in the thyroid gland and in cultured thyrocytes
- Author
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Massimo Santoro, Daniela Califano, Paola Bruni, Angelo Boccia, Giuseppe Viglietto, Giovanni Santelli, Barbara Belletti, Maria Teresa Vento, Alfredo Fusco, Gustavo Baldassarre, G. Manzo, Monica Fedele, G., Viglietto, D., Califano, P., Bruni, G., Baldassarre, M. T., Vento, B., Belletti, M., Fedele, G., Santelli, A., Boccia, G., Manzo, Santoro, Massimo, and Fusco, Alfredo
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endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,Messenger ,Thyroid Gland ,Thyrotropin ,drug effects, Goiter ,Cultured, Gene Expression Regulation ,Endocrinology ,Animals, Cell ,Cells, Cultured ,Protein Synthesis Inhibitors ,biology ,Goiter ,pharmacology, Protein Synthesis Inhibitor ,analysis, Rats, Rat ,Thyroid ,General Medicine ,pharmacology, RNA ,medicine.anatomical_structure ,administration /&/ dosage, Nucleic Acid Synthesis Inhibitor ,hormones, hormone substitutes, and hormone antagonists ,Signal Transduction ,medicine.drug ,endocrine system ,medicine.medical_specialty ,Follicular cell ,Thyroid-stimulating hormone ,Thyroid peroxidase ,In vivo ,Internal medicine ,medicine ,Animals ,Humans ,genetics, Humans, Iodide ,RNA, Messenger ,Nucleic Acid Synthesis Inhibitors ,Thyroid hormone receptor ,Thymosin ,drug effects/metabolism, Thyrotropin ,Iodides ,Rats, Inbred F344 ,Rats ,Inbred F344, Signal Transduction, Thymosin ,Gene Expression Regulation ,biology.protein ,Propylthiouracil ,genetics, Thyroid Gland ,pharmacology - Abstract
OBJECTIVE: To investigate the expression of thymosin beta10 - a small conserved acidic protein involved in the inhibition of actin polymerization - in human and experimental thyroid goiters as well as the regulation exerted by TSH on thymosin beta10 expression in thyroid follicular cells both in vivo and in vitro. DESIGN: To this aim, we have used 5 bioptic specimens from patients affected by thyroid goiter, a well known experimental model of thyroid goitrogenesis (rat fed with the drug propylthiouracil) and a cultured rat thyroid cell line (PC Cl 3 cells) as a model system. RESULTS: We report that the mRNA expression of thymosin beta10 is markedly enhanced in human goiters compared with normal thyroid. In vivo results showed that the steady-state level of thymosin beta10 mRNA is up-regulated in the thyroid gland of propylthiouracil-fed rats in parallel with follicular cell proliferation: iodide administration to goitrous rats, which induced a marked involution of thyroid hyperplasia, reduced the mRNA level of thymosin beta10. Finally, in vitro studies showed that in cultured rat thyrocytes, the expression of thymosin beta10 mRNA is induced in a time- and dose-dependent manner by the activation of pathways which are mitogenic for thyroid cells (i.e. the protein kinase (PK) A and PKC pathways). CONCLUSION: Taken together, the findings reported here demonstrate that thymosin beta10 expression is regulated by extracellular signals that stimulate growth of thyroid cells both in vitro and in vivo, and suggest a role for this protein in thyroid diseases characterized by proliferation of follicular cells.
- Published
- 1999
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