Expression of obese(OB) gene, and production and secretion of leptin in a human choriocarcinoma-derived cell-line, Be Wo

A.14 EXPRESSION OF OBESE(OB) GENE, AND PRODUCTION AND SECRETION OF LEPTIN IN A HUMAN CHORIOCARCINOMA-DERIVED CELL-LINE, BE WO. S. Yura, N. Sagawa, T. Matsumoto, H. Mise, B. Liu, *H. Masuzaki, *Y. Ogawa, *K. Hosoda, *K. Nakao. Department of Obstetrics and Gynecology, and *Department of Clinical Science and Mcdicinc. Kyoto Univenity Graduate School of Medicine, Kyoto, Japan. Objectives: WC previously roporled thal plasma lcptin levels in pregnant women are significantly higher than those in body mass index (BMI)-matched non-pregnant women, thal the obcsc gone is expressed in the human placenta, and that leptin is secreted from placenta into both malemal and fc~al circulations. To elucidate the regulation of production and secretion of leptin in human trophoblast cells, we examined obese gene expression and leptin secretion in BeWo cells, a choriocarcinoma-derived cell-line. Methods: BeWo cells were cultured in RPM1 1640 medium with 10% FCS. After reaching confluence, the cells were treated with Forskolin (2 - 20 mM) for 48 hours, and the morphological changes, hCG secretion, leptin secretion, and obese gene expression were examined. Concentrations of hCG were determined by an ELISA. Leptin concentrations were determined by a radioimmunoassay specific for human leptin (Hosoda et al, BBRC 221: 234, 1996). Obese gene expression was examined by Northern blot analysis. Results: BeWo cells aggregated and transformed to polynuclear cells, and the hCG concentrations in the culture media increased in time- and dose-dependent manners after Forskolin treatment. Leptin concentrations in the media also increased by Forskolin in time- and dose-dependent manners. Northern blot analysis revealed that obese gene expression in BeWo cell was stimulated by the trealment with Forskolin. Conclusions: The present study revealed that the obese gene is expressed in BeWo cells and that Forskolin treatment stimulated both obese gene expression and leptin secretion in BeWo cells, suggesting thaw BeWo cell may become a useful model in studying leptin secretion in placental trophoblast cells.

Placenta

(1997),

Vol. 18