c-Jun is regulated by combination of enhanced expression and phosphorylation in acute-overloaded rat heart

Autor(es)

Nadruz Júnior, Wilson ^[1] ; Kobarg, Claudia B. ; Kobarg, Jorg ; Franchini, Kleber G. ^[4]

Afiliação do(s) autor(es)

^[1] Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas - Brasil

^[4] Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas. Departamento de Clínica Médica - Brasil

• Tipo de documento: Artigo Científico
• Fonte: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY; v. 286, n. 2, p. H760-H767, Feb. 2004.
• Área do conhecimento: Ciências da Saúde - Medicina
• Assunto(s): Sistema cardiovascular Miocárdio Expressão gênica Antracenos Proteínas quinases

Resumo

The transient increase in the expression of transcription factors encoded by immediate-early genes has been considered to play a critical role in the coordination of early gene expression during the hypertrophic growth of cardiac myocytes. Here, we investigated the regulation of c-Jun and its upstream activators JNKs in the myocardium of rats subjected to acute pressure overload induced by transverse aortic constriction. Western blotting and immunohistochemistry analysis demonstrated that both JNK1 and JNK2 were transiently activated by pressure overload, but only JNK1 was activated at the nuclei of cardiac myocytes. JNK1 activation was paralleled by phosphorylation of c-Jun at serine-63 in the myocardial nuclear fraction and by an increase in c-Jun expression in cardiac myocytes. A consistent increase in DNA binding of activator protein-1 (AP-1) complex was observed after 10 and 30 min of pressure overload and Supershift assays confirmed that c-Jun was a major component of activated AP-1 complex. Moreover, experiments performed with the specific JNK inhibitor SP-600125 abolished c-Jun phosphorylation and markedly attenuated its expression as well as the expression of the fetal gene -myosin heavy chain. Overall, these findings demonstrate a molecular basis for load-induced activation of c-Jun in cardiac myocytes and its connection with the regulation of fetal gene, characteristic of the acute response to pressure overload. (AU)

• Processo FAPESP: 99/10263-0 - Sinalizacao celular durante aumento de tensao no coracao: ativacao e regulacao de vias celulares de crescimento cardiaco.
• Beneficiário: Wilson Nadruz Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 01/11698-1 - Mecanismos de sinalização celular ativados por sobrecarga mecânica: implicações na hipertrofia e remodelamento miocárdicos
• Beneficiário: Kleber Gomes Franchini
• Modalidade de apoio: Auxílio à Pesquisa - Temático