Objective: Excessive exposure to glucocorticoids (GCs) during gestation period not only causes fetal growth retardation but also increases the risk of adult metabolic diseases. 11 Beta-hydroxysteroid dehydrogenase (11β-HSD2) is a kind of glucocorticoid metabolic enzymes, which plays a role to the placental GCs barrier during gestation period. The aim of this study is to investigate the effect and mechanism of sonic hedgehog (Shh) signalling on regulation the expression of 11β-HSD2 and the progress of syncytialization in the placenta.
Methods: Cytotrophoblasts was extracted from normal full-term pregnancy placenta. They were induced to Shh conditioned medium, a specific inhibitor of Shh signalling pathways cyclopamine, and Smo agonist purmorphamine. The luciferase gene report was used to detect Shh conditioned medium activity. shRNA was used to knock-down of Gli1, Gli2, and Gli3. The Bewo cells were used as a human trophoblast cell model. PCR, western blotting, immunofluorescence, and ELISA were used to measure the levels of ZO-1, β-hCG, membrane fusion protein factor Synctin A, and transcription factor GCMa.
Results: Gli was actived in Shh-conditioned medium. Shh-conditioned medium increased the protein levels of Gli1 as measured with western blotting. Shh antagonist cyclopamine decreased Shh pathway-stimulated expression of 11β-HSD2. In addition, knock-down of Gli with shRNA significantly decreased 11β-HSD2 mRNA and protein levels. Shh reduced the protein expression of ZO-1 while stimulated the production of β-hCG. Also, Shh increased the mRNA expression of Synctin A and GCMa.
Conclusion: These results suggested that the Shh signal pathway was expressed in human placenta. Protein and mRNA levels of 11β-HSD2 increased with Shh and membrane receptor proteins Smo. Additionally, we also found that transcription factor Gli1 and Gli2, and Gli3 upregulated the expression of including 11β-HSD2, in which Gli1 played the main role. These indicated that Shh signalling pathways regulate the expression of 11β-HSD2. These also indicated that Shh signalling pathways regulate the process of trophoblast cells fusion.
Funding: This work was supported by the National Natural Science Foundation of China (81170787) Zhejiang Provincial Program for the Cultivation of High-Level Innovative Health Talents(2015).
01 Oct 2015 - 03 Oct 2015