Dysfunction of Shh signaling impaired trophoblast motility and autophagy is involved in poor placentation of recurrent miscarriage

Background: In early pregnancy, the placenta anchors the conceptus and supports embryonic development and survival. This study aimed to investigate the underlying functions of Shh signaling on recurrent miscarriage, an serious disorder of pregnancy. Methods: Immunofluorescence and immunohistochemistry were used to detect protein expression and its location in placental tissues. Quantitative real-time RT-PCR and Western blot analysis were performed to examine mRNA and protein levels, respectively. Lentiviruses expressing short hairpin RNA were used to knock down the target genes. Cell invasion and migration were performed by with or without Matrigel-coated transwell, respectively. Primary trophoblast migration was performed by villous explant assay. RNA-sequence was used to investigate the genes transcription profile. CCK-8 assay was used to evaluate cell viability. Flow cytometry was used to evaluate cell apoptosis. Results: Our results showed that Shh and Gli2 were mainly located in cytotrophoblasts (CTBs), Ptch was mainly located in syncytiotrophoblasts (STBs), while Smo and Gli3 were expressed in both CTBs and STBs. Compared to the gestational age-matched normal human placenta, the expression of Shh was significantly decreased in recurrent miscarriage. Furthermore, inhibition of Shh signaling impaired motility of JAR cells via regulating the expression of Gli2 and Gli3 to decrease AKT Ser473 phosphorylation, elevate E-cadherin and VEGFA. Intriguingly, inhibition of Shh signaling also enhanced autophagy and autolysosome. Additionally, knockdown BECN1 reversed the effect of Gant61 on motility inhibition. Conclusion: Our results indicated that dysfunction of Shh signaling impaired trophoblast motility, angiogenesis and activated autophagy in villous trophoblast, which would contribute to the pathophysiology of recurrent miscarriage.