Expression and Activity of 25-Hydroxyvitamin D-1α-Hydroxylase Are Restricted in Cultures of Human Syncytiotrophoblast Cells from Preeclamptic Pregnancies

• Published in: The journal of clinical endocrinology and metabolism 2002-08, Vol.87 (8), p.3876-3882
• Main Authors: Díaz, Lorenza, Arranz, Celeste, Avila, Euclides, Halhali, Ali, Vilchis, Felipe, Larrea, Fernando
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D3 1-alpha-Hydroxylase - genetics; 25-Hydroxyvitamin D3 1-alpha-Hydroxylase - metabolism; Biological and medical sciences; Cell Differentiation - physiology; Cells, Cultured; Chorionic Gonadotropin - genetics; Diseases of mother, fetus and pregnancy; Female; Gene Expression Regulation, Enzymologic - physiology; Gynecology. Andrology. Obstetrics; Humans; Insulin-Like Growth Factor I - genetics; Medical sciences; Pre-Eclampsia - metabolism; Pregnancy; Pregnancy. Fetus. Placenta; RNA, Messenger - analysis; Steroid Hydroxylases - biosynthesis; Steroid Hydroxylases - metabolism; Steroid Hydroxylases - pharmacology; Tritium; Trophoblasts - cytology; Trophoblasts - enzymology; Tropical medicine
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jcem.87.8.8730

The human placenta synthesizes 1,25-dihydroxyvitamin D3 and expresses the vitamin D receptor. Because preeclampsia (PE) is associated with low circulating levels of maternal 1,25-dihydroxyvitamin D3 and IGF-I, it is possible that alterations in calcium metabolism seen in PE could occur at the level of the fetoplacental unit. In this study, the patterns of gene expression and enzyme activity of 25-hydroxyvitamin d-1α-hydroxylase (1α-hydroxylase) and the abundance of IGF-I mRNA in placentas from normal (NT) and PE-complicated pregnancies were investigated. Cultured syncytiotrophoblast cells from preeclamptic placentas had only one tenth the activity of 1α-hydroxylase and did not respond to IGF-I, when compared with NT cultures. Similarly, the levels of 1α-hydroxylase mRNA in syncytiotrophoblast cells from PE placentas under basal and IGF-I-stimulated conditions were significantly reduced. In contrast, IGF-I mRNA levels were found to increase during the differentiation process, with no differences between NT and PE cultures. These results support the role of placenta as a contributor to the abnormalities observed in calcium metabolism in PE.