Leptin and neuropeptide Y gene expression in human placenta: Ontogeny and evidence for similarities to hypothalamic regulation

The objective of the present study was to examine the impact of preeclampsi a on the relation of leptin and neuropeptide Y (NPY) gene expression in hum an placenta. A second goal was to monitor the change of leptin messenger RN A (mRNA) with increasing gestational age. Placental tissue was obtained from 17 premature deliveries, 18 term deliver ies, and 10 mothers with preeclampsia. Gene expression of leptin, NPY, and two housekeeping genes (beta-actin and glyceraldehyde-3-phosphate dehydroge nase was quantified using real-time PCR. The leptin/beta-actin mRNA ratio was significantly higher in specimens of p atients with preeclampsia than in those of gestational age-matched controls (0.63 +/- 0.23 vs. 0.09 +/- 0.04 relative U (RU); P = 0.03). NPY/beta-acti n mRNA was significantly reduced in the preeclampsia group (0.003 +/- 0.001 us. 0.026 +/- 0.008 RU in controls; P = 0.01). The NPY/leptin ratio was 0. 11 +/- 0.09 for preeclamptic placenta samples and 1.7 +/- 0.6 RU for the co ntrols (P = 0.02). The leptin/beta-actin ratio was significantly lower in p lacenta from premature deliveries than in term deliveries (0.02 +/- 0.004 u s. 0.12 +/- 0.05 RU; P = 0.01). Similar results were obtained for normaliza tion to glyceraldehyde-3-phosphate dehydrogenase mRNA. Our data suggest an increase of placental leptin production with gestationa l age. In patients with preeclampsia, elevated leptin expression goes along with suppressed NPY expression. This resembles hypothalamic regulation.