INVESTIGADORES
RIERA Maria Fernanda
artículos
Título:
Assessment of the roles of mitogen activated protein kinase (MAPK) and phosphatidyl inositol 3-kinase/protein kinase B (PI3K/PKB) pathways in basic fibroblast growth factor (bFGF) regulation of Sertoli cell function
Autor/es:
RIERA MARÍA FERNANDA; MERONI SILVINA BEATRIZ; PELLIZZARI ELIANA; CIGORRAGA SELVA BEATRIZ
Revista:
JOURNAL OF MOLECULAR ENDOCRINOLOGY
Referencias:
Año: 2003 vol. 31 p. 279 - 289
ISSN:
0105-6263
Resumen:
Basic fibroblast growth factor (bFGF) belongs to the large set of intratesticular regulators that provide
the fine tuning of cellular processes implicated in the maintenance of spermatogenesis. The aim of the
present study was to determine the participation of mitogen-activated protein kinase (MAPK) and
phosphatidyl inositol 3-kinase/protein kinase B (PI3K/PKB) pathways in bFGF regulation of Sertoli cell
function. Twenty-day-old rat Sertoli cell cultures were used. Stimulation of the cultures with bFGF showed
a time-dependent increment in phosphorylated MAPK and PKB levels that reached maximal values in
5-min incubations. MAPK kinase inhibitors U0126 (U) and PD98059 (PD) and a PI3K inhibitor wortmannin
(W) were able to block the stimulatory effects of bFGF on phosphorylated MAPK and PKB levels
respectively. The participation of MAPK- and PI3K/PKB-signaling pathways in the regulation by bFGF of
two well-known Sertoli cell-differentiated functions, lactate and transferrin production, was next explored.
As for lactate production, PD and W did not modify the ability of bFGF to stimulate lactate production.
However, a combination of PD and W partially impaired the increase in lactate production elicited by
bFGF. The participation of MAPK- and PI3K/PKB-signaling pathways in the regulation by bFGF of
glucose uptake and lactate dehydrogenase (LDH) activity was also analysed. In this respect, it was
observed that W markedly decreased basal and bFGF-stimulated glucose uptake and that U and PD did
not modify it. On the other hand, U and PD decreased the stimulation of LDH activity by bFGF whereas
W did not modify it. As for transferrin production, while both MAPK kinase inhibitors partially decreased
the ability of bFGF to stimulate transferrin secretion, the PI3K inhibitor did not modify it. In summary, the
results demonstrated that bFGF stimulates MAPK- and PI3K/PKB-dependent pathways in rat Sertoli
cells. Moreover, these results showed that while bFGF utilizes the MAPK pathway to regulate transferrin
production and LDH activity, it uses the PI3K/PKB pathway to regulate glucose transport into the cell.