Análise da expressão das proteínas dos genes de resposta primária, proteínas da família Fos e Jun, em culturas primárias de supra-renal de rato tratadas com ACTH e FGF2.

Abstract

POLLI, S. THE EXPRESSION OF EARLY PRIMARY GENE PROTEINS, FOS AND JUN FAMILY PROTEINS, IN RAT ADRENAL PRIMARY CULTURES TREATED WITH ACTH AND FGF2. (2007) 90fl MASTER thesis in Morphofunctionals Sciences, ICB. Universidade de Sao Paulo, Sao Paulo. There are evidences that in vivo the adrenocorticotropic hormone (ACTH) displays an important role in the balance of proliferation and cellular death in the adrenal gland, besides its steroidogenic function. The early response gene proteins, among them Fos and Jun family, are components of the transcription factor AP-1 that, depending on its composition, could be related with proliferation, differentiation or cellular death. Different experimental models have been used to study the action of ACTH in the adrenal gland and the in vitro system is one of them. In this work we have been used adrenocortex cells of rat primary cultures, Glomerulosas and Fasciculata/Reticularis cells to evaluate, by immunocytochemistry and immunoblotting, the effects of ACTH and fibroblast growth factor (FGF2) in the expression of c-Fos, FosB, Fra1, Fra2, c-Jun, JunB and JunD proteins, and in such wise as to predict the composition of AP1 complex. The results of this study showed that ACTH and FGF2 treatments modify the expression pattern of these proteins, inducing mainly a consistent and expressive increase of JunB protein expression in the ACTH-treated cells, suggesting an AP1 composition with JunB/c-Fos or FosB, which are compatible with a negative regulator of cell cycle progression. On the other hand, FGF2 treatments indicate the composition of c-Jun/c-Fos or FosB or Fra-2 complexes, which suggest a complex related with induction of proliferation. These results are in agreement with the biological effects observed in rat adrenal primary culture treated with ACTH and FGF2, respectively, inhibition and cellular proliferation. On the whole, these results contribute to explain one of the probable mechanisms by which ACTH proceed as an anti-mitogenic factor in normal adrenal cell cultures. KeyWord: rat adrenal culture cells, Fos and Jun proteins, ACTH, FGF2. LISTA DE ABREVIATURAS AP-1 – Activator Protein 1 ATF Activing Transcriptor Factor BSA Bovine Serum Albumin Cdks Cyclin Dependent Kinase CKIs CDK Inhibitors CRF – Corticotropin-Releasing Hormone CRFr Corticotropin-Releasing Hormone Receptor CRE – cAMP Response Element CREB cAMP Response-Element Binding-Protein cAMP Cyclic Monophosfate of Adenosine DNA Deoxyribonucleic Acid DMEM – Meio Eagle Modificado por Dulbecco ERK Extracellular Signal-Regulated kinases FGF2 – Fibroblast Growth Factor 2 GABA Gamma-Aminobutyric Acid HPA Hypothalamus-Pituitary-Adrenal JNK – Jun NH2-Terminal Kinases MAPK – Mitogen Activated Protein Kinases MC2r – Melanocortin Receptor PDGF Platelet-Derived Growth Factor P450scc Cholesterol Side-Chain Cleavage PKA – Protein Kinase A RNA Ribonucleic Acid SFB – Serum Fetal Bovine TRE PMA Responsive Element