INVESTIGADORES
MAYMO Julieta Lorena
congresos y reuniones científicas
Título:
Mechanisms of leptin action on placental cell survival
Autor/es:
AYELÉN TORO; JULIETA MAYMÓ; FEDERICO IBARBALZ; ANTONIO PÉREZ-PÉREZ; JUAN CARLOS CALVO; VICTOR SÁNCHEZ MARGALET; CECILIA VARONE
Lugar:
Sevilla
Reunión:
Congreso; XXXV Congreso de la Sociedad Española de Bioquímica y Biología Molecular; 2012
Institución organizadora:
SEBBM
Resumen:
Fetal-maternal dialogue during implantation involves multiple
regulators such as leptin. This 16KD protein plays diverse roles
in placental growth and survival.
Previous results from our group demonstrated that leptin
increases cell proliferation and survival in JEG-3 and BeWo cells.
We also demonstrated that leptin expression is tightly regulated
by different placental regulators.
Objectives: The aim of the present work is to study the mechanisms
involved in leptin rol on placental apoptosis.
Methods: BeWo and Swan cells, and human term placental
explants were used. Western blot analyses were carried out to
detect leptin, caspase 3, Bcl-2, Bax and p53 expression. Transfection
assays with reporter constructs were used to determine leptin
effect on different transduction pathways
Results: Leptin treatment diminished the proteolysis of caspase-
3 in a dose dependent manner. Moreover the diminution in
endogenous leptin by treatment with an antisense oligonucleotide
(24 lM) increases cellular apoptosis measured by caspase-3 activation.
Bcl-2 and Bax levels were determined after leptin treatment
and the relationship between them calculated. Leptin
enhanced Bcl2/Bax relation. On the other hand leptin diminished
the expression of a reporter plasmid containing Bax promoter.
The expression of the key cell cycle regulator p53 was also determined.
Leptin diminished p53 protein level dose dependently.
Conclusions: All these results reinforce the notion of leptin as a
placental cytokine with the function of promoting survival of
placental cells.