IGF-1 or insulin, and the TSH cyclic AMP cascade separately control dog and human thyroid cell growth and DNA synthesis, and complement each other in inducing mitogenesis.


Autoria(s): Deleu, Sandrine; Pirson, Isabelle; Coulonval, Katia; Drouin, Annick; Taton, Martine; Clermont, Frédéric; Roger, Pierre P.; Nakamura, Takahiro; Dumont, Jacques Emile; Maenhaut, Carine
Data(s)

01/03/1999

Resumo

The regular doubling of cell mass, and therefore of cell protein content, is required for repetitive cell divisions. Preliminary observations have shown that in dog thyrocytes insulin induces protein accumulation but not DNA synthesis, while TSH does not increase protein accumulation but triggers DNA synthesis in the presence of insulin. We show here that EGF and phorbol myristate ester complement insulin action in the same way. HGF is the only factor activating both protein accumulation and DNA synthesis. The effects of insulin on protein accumulation and in permitting the TSH effect are reproduced by IGF-1 and are mediated, at least in part by the IGF-1 receptor. The concentration effect curves are similar for both effects. Similar results are obtained in human thyrocytes. They reflect true cell growth, as shown by increases in RNA content and cell size. Carbachol and fetal calf serum also stimulate protein synthesis and accumulation without triggering DNA synthesis, but they are not permissive for the mitogenic effects of TSH or of the general adenylate cyclase activator, forskolin. Moreover the mitogenic effect of TSH greatly decreased in cells deprived of insulin for 2 days although these cells remain hypertrophic. Hypertrophy may therefore be necessary for cell division, but it is not sufficient to permit it. Three different mechanisms can therefore be distinguished in the mitogenic action of TSH: (1) the increase of cell mass (hypertrophy) induced by insulin or IGF-1; (2) the permissive effect of insulin or IGF-1 on the mitogenic effect of TSH which may involve both the increase of cell mass and the induction of specific proteins such as cyclin D3 and (3) the mitogenic effect of the TSH cyclic AMP cascade proper.

Journal Article

Research Support, Non-U.S. Gov't

info:eu-repo/semantics/published

Formato

No full-text files

Identificador

uri/info:doi/10.1016/S0303-7207(99)00005-2

uri/info:pii/S0303-7207(99)00005-2

uri/info:pmid/10375016

local/VX-005234

http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/57733

Idioma(s)

en

Fonte

Molecular and cellular endocrinology, 149 (1-2

Palavras-Chave #Sciences bio-médicales et agricoles #Animals #Cell Division -- drug effects #Cells, Cultured #Cyclic AMP -- metabolism #DNA -- biosynthesis #Dogs #Drug Interactions #Epidermal Growth Factor -- pharmacology #Forskolin -- pharmacology #Humans #Insulin -- pharmacology #Insulin-Like Growth Factor I -- pharmacology #Mitogens -- pharmacology #Protein Biosynthesis #Tetradecanoylphorbol Acetate -- pharmacology #Thyroid Gland -- cytology #Thyroid Gland -- drug effects #Thyroid Gland -- metabolism #Thyrotropin -- pharmacology
Tipo

info:eu-repo/semantics/article

info:ulb-repo/semantics/articlePeerReview

info:ulb-repo/semantics/openurl/article