caa a22 4500 463254376 CHVBK 20180405153350.0 cr unu---uuuuu 170326e20071101xx s 000 0 eng 10.1007/s10571-006-9084-2 doi (NATIONALLICENCE)springer-10.1007/s10571-006-9084-2 Thyroid Hormones Reorganize the Cytoskeleton of Glial Cells Through Gfap Phosphorylation and Rhoa-Dependent Mechanisms [Elektronische Daten] [Ariane Zamoner, Cláudia Funchal, Maria Jacques-Silva, Carmem Gottfried, Fátima Regina Mena Silva, Regina Pessoa-Pureur] Thyroid hormones (3,5,3′-triiodo-l-thyronine, T3; 3,5,3′,5′-l-tetraiodothyronine, T4; TH) play crucial roles in the growth and differentiation of the central nervous system. In this study, we investigated the actions of TH on proliferation, viability, cell morphology, in vitro phosphorylation of glial fibrillary acidic protein (GFAP) and actin reorganization in C6 glioma cells. We first observe that long-term exposure to TH stimulates cell proliferation without induce cell death. We also demonstrate that after 3, 6, 12, 18, and 24h treatment with TH, C6 cells and cortical astrocytes show a process-bearing shape. Furthermore, immunocytochemistry with anti-actin and anti-GFAP antibodies reveals that TH induces reorganization of actin and GFAP cytoskeleton. We also observe an increased in vitro 32P incorporation into GFAP recovered into the high-salt Triton insoluble cytoskeletal fraction after 3 and 24h exposure to 5×10−8 and 10−6M T3, and only after 24h exposure to 10−9M T4. These results show a T3 action on the phosphorylating system associated to GFAP and suggest a T3-independent effect of T4 on this cytoskeletal protein. In addition, C6 cells and astrocytes treated with lysophosphatidic acid, an upstream activator of the RhoA GTPase pathway, totally prevented the morphological alterations induced by TH, indicating that this effect could be mediated by the RhoA signaling pathway. Considering that IF network can be regulated by phosphorylation leading to reorganization of IF filamentous structure and that alterations of the microfilament organization may have important implications in glial functions, the effects of TH on glial cell cytoskeleton could be implicated in essential neural events such as brain development. Springer Science+Business Media, Inc., 2007 Thyroid hormones nationallicence C6 glioma cells nationallicence astrocytes nationallicence cytoskeleton nationallicence GFAP phosphorylation nationallicence RhoA signaling pathway nationallicence Zamoner Ariane Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut Funchal Cláudia Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut Jacques-Silva Maria Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut Gottfried Carmem Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut Silva Fátima Regina Mena Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brasil aut Pessoa-Pureur Regina Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/7(2007-11-01), 845-865 0272-4340 27:7<845 2007 27 10571 https://doi.org/10.1007/s10571-006-9084-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10571-006-9084-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zamoner Ariane Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut NATIONALLICENCE 700 1- Funchal Cláudia Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut NATIONALLICENCE 700 1- Jacques-Silva Maria Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut NATIONALLICENCE 700 1- Gottfried Carmem Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut NATIONALLICENCE 700 1- Silva Fátima Regina Mena Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brasil aut NATIONALLICENCE 700 1- Pessoa-Pureur Regina Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil aut NATIONALLICENCE 773 0- Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/7(2007-11-01), 845-865 0272-4340 27:7<845 2007 27 10571 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer