Sonic hedgehog through Gli2 and Gli3 is required for the proper development of placental labyrinth

Abstract

Sonic hedgehog (Shh) functions as a conserved morphogen in the development of various organs in metazoans ranging from Drosophila to humans. Here, we have investigated the potential roles and underlying mechanisms of Shh signaling in murine placentation. Immunostaining revealed the abundant expression of the main components of Shh pathway in both the trophectoderm of blastocysts and developing placentas. Disruption of Shh led to impaired vascularogenesis of yolk sac, less branching and malformation of placental labyrinth, thereby leading to a robust decrease in capacity of transplacental passages. Moreover, placenta-specific gene incorporation by lentiviral transduction of mouse blastocysts and blastocyst transplantation robustly knocked down the expression of Gli3 and Gli2 in placenta but not in embryos. Finally, Gli3 knockdown in Shh−/− placentas partially rescued the defects of both yolk sac and placental labyrinth, and robustly restored the capacity of transplacental passages. Gli2 knockdown in Shh+/− placentas affected neither the capacity of tranplacental passages nor the vascularogenesis of yolk sac, however, it partially phenocopied the labyrinthine defects of Shh−/− placentas. Taken together, these results uncover that both Shh/Gli2 and Shh/Gli3 signals are required for proper development of murine placentas and are possibly essential for pregnant maintenance.

Glioma-associated Oncogene 2 Is Essential for Trophoblastic Fusion by Forming a Transcriptional Complex with Glial Cell Missing-a

“…Therefore, our findings not only uncover a so far uncharacterized role of HH signaling but also expand the list of tissues and cells influenced by HH signaling. These findings correspond to our previous results showing that knockout of SHH (SHH Ϫ/Ϫ ) in murine placentas leads to defects in the expression of syncytial markers and development of the placental labyrinth and that placenta-specific knockdown of GLI2 by lentiviral GLI2-shRNA in SHH Ϫ/ϩ murine placentas phenocopies the labyrinthine defects of SHH Ϫ/Ϫ placentas (18). However, to determine whether GLI2 indeed promotes trophoblastic fusion, genetic evidence from trophoblast-specific knockout of GLI2 in murine placenta is worthy of further investigation.…”

“…In the absence of HH, PTCH1 represses SMO activity and, thereby, GLI3 undergoes proteolytical cleavage into its repressor within the primary cilium, resulting in inactivation of HH signaling (17). Our previous studies have shown that the main components of the HH signaling pathway are expressed robustly in both human and murine placentas (18,19). In human placental villi, Desert hedgehog and Indian hedgehog are expressed predominantly in the villous core and trophoblast layers, respectively, whereas SHH is expressed in both trophoblast layers and villous cores.…”

Up-regulation of 11β-Hydroxysteroid Dehydrogenase Type 2 Expression by Hedgehog Ligand Contributes to the Conversion of Cortisol Into Cortisone

“…Thus, our findings not only uncover a hitherto uncharacterized role of HH signaling but also expand the list of tissues and cells influenced by HH signaling. These findings correspond to our previous results showing that knockout of SHH (SHH Ϫ/Ϫ ) in murine placentas leads to defects in the development of placental labyrinth, and that placenta-specific knockdown of GLI2 by lentiviral GLI2-shRNA in SHH Ϫ/ϩ murine placentas phenocopies labyrinthine defects of SHH Ϫ/Ϫ placentas (17). However, whether GLI2 indeed promotes 11␤-HSD2 expression, genetic evidence from trophoblast-specific knockout of GLI2 in murine placenta is worthy of further investigation.…”

“…Recently, we demonstrated the expression patterns of HH ligands and activity of the HH signaling pathway in both human and murine placentas, and further confirmed the versatile roles of HH signaling in placental development and functions including steroidogenesis, epithelialmesenchymal transition and syncytialization (2,(15)(16)(17). In the present study, we have revealed that activation of HH pathway promotes the conversion of active cortical to inactive cortisone through GLI2-mediated induction of 11␤-HSD2 expression in human tropoblasts.…”

Signaling Cascades Governing Cdc42-Mediated Chondrogenic Differentiation and Mensenchymal Condensation

“…HEK293T packaging cells for generating the lentiviruses and 293GPG packaging cells for generating retroviruses were cultured as previously described (Ory et al 1996;Pan et al 2015). After confluence, C3H10T1/2 cells were starved for 12 hr and then pretreated with various inhibitors (SB203580 at 20 mM, ML141 at 40 mM, IPA-3 at 10 mM, and anisomycin at 5 mM) for 3 hr followed by further treatment with recombinant human BMP2 (rhBMP2) or TGF-b at 10 ng/ml for indicated times.…”