Efeitos do VEGF e do bFGF sobre a expressão da aromatase P450 em cultivo de células placentárias provenientes de bovinos clonados e não clonados / VEGF and bFGF effects on P450 aromatase expression of cultivated placental cells from cloned and non-cloned bovines

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are important regulators of placental development and function. Their effects on the steroidogenic enzyme aromatase P450 (P450arom) expression from bovine placenta at different gestational stages (90 - 270 days) were evaluated by immunocytochemistry. Moreover, we compared the effects of these growth factors on P450arom expression between cloned and non cloned bovine placental cells. P450arom was localized exclusively in trophoblast giant cells cytoplasm, and its expression reached lowest levels at day 150 of gestation in comparison to the remaining evaluated gestational stages. VEGF (50 ng/mL) influenced significantly P450arom expression at days 150 and 270, whereas bFGF (10 ng/mL) was effective in stimulating P450arom expression particularly during late gestation (day 270). The two factors combined (bFGF+VEGF) inhibited P450arom expression during early gestation (day 90), but, in contrast, stimulated it at days 150 and 270 of pregnancy (P<0.05). In cloned bovine placental cells, P450arom expression was similar to non-cloned cells in the control and VEGF groups, however, bFGF and both factors together inhibited it significantly (P<0.05). In all groups analyzed, P450arom expression presented rising pattern over the duration of the culture, reaching maximal values at 96 hours of incubation. Thus, the present study demonstrated distinct and stage-specific effects of these growth factors on bovine placenta P450arom expression in vitro. We concluded that these growth factors act as potent steroidogenic enzymes regulators, and, under the established culture conditions, placental cells from cloned bovines presented distinct answer pattern compared to non cloned placental cells at the same gestational stage.

ASSUNTO(S)

aromatase fatores de crescimento placenta bovinos aromatase cloned cattle bovine growth factors placenta clones

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