Leptin action and leptin receptor signaling in human trophoblasts

ANTONIO PÉREZ PÉREZ; FLORA SÁNCHEZ-JIMÉNEZ; JULIETA L. MAYMÓ; YÉSICA GAMBINO; JOSÉ DUEÑAS; CECILIA L. VARONE; VÍCTOR SÁNCHEZ-MARGALET

The Placenta: Development, Function and Diseases

Nova Science Publishers, Inc

Año: 2013; p. 43 - 58

Leptin is a pleiotropic hormone, mainly secreted by the adipose tissue, with a central role in the regulation of metabolism and energy homeostasis. Nevertheless, placenta is the second leptin producing tissue in humans, where leptin may be an important local growth factor acting in an autocrine or paracrine manner. In fact, leptin is now considered an important molecule signaling the reproductive system, regulating the production of gonadotropins, blastocyst formation and implantation, normal placentation, as well as feto-placental communication. Moreover, leptin seems to play an important role in pregnancy and may be an important factor and/or marker in pregnancy pathology. Leptin has an anti-apoptotic effect on trophoblast cells, preventing cell death after serum deprivation. Moreover, leptin promotes cell growth and proliferation, stimulating DNA and protein synthesis. These effects are mediated by the long isoform of the leptin receptor (LEPRb) via the activation of well-known signaling pathways, such as JAK-STAT, PI3K and MAPK (ERK) in human trophoblastic cell lines, as well as trophoblast explants from human donors. Besides, the participation of the RNA binding protein Sam68 in LEPR signal transduction from placental trophoblast has also been demonstrated. Thus, leptin promotes the expression and tyrosine phosphorylation of Sam68, which mediates the trophic and proliferative effect of leptin in human trophoblastic cells. Finally, Sam68 seems to mediate the growth effect of leptin in human trophoblasts. © 2013 Nova Science Publishers, Inc. All rights reserved