Investigation of the effect of αvβ3 integrin and CD9 interaction on excessive trophoblast invasion in pregnancies with Placenta Accreta Spectrum

Objective: We investigated the hypothesis that αVβ3 integrin and CD9 tetraspanin molecules, which we think may cause abnormal cell migration in the Placenta Accreta Spectrum (PAS), characterized by excessive trophoblast cell invasion into the uterus, can regulate trophoblast cell migration through cell-cell interactions. Method: Three study groups were formed; Pregnancies with Placenta Accreta Spectrum, pregnancies resulting in cesarean delivery and Control group (pregnancies resulting in normal delivery). For each group, hysterectomy materials or term placentas were obtained from the patients after delivery. Tissue samples taken from the invasion area were firstly stained with Hematoxylin-Eosin and were examined morphologically. Then, Double Immunofluorescent staining was performed with αVβ3 integrin and CD9 antibodies using CYT7 for the characterization of Extravilloustrophoblast cells and Vimentin for the characterization of decidual cells. As a result of staining, expression changes and localizations of these proteins were determined. In addition, Western blot analysis was performed for αVβ3 integrin and CD9 molecules with fresh tissue samples, This analysis quantitatively determined whether there was an increase in protein expression amounts between the groups. Results: There was a significant decrease in αVβ3 integrin in the cesarean section group compared to the PAS group. There was no significant difference between the groups in the WB analysis performed for CD9. In double immunofluorescent staining, both proteins showed positive staining in all groups. As a marker, αVβ3 integrin is more intensely expressed in EVT cells. Conclusion: Recurrent cesarean scar may play a role in the development of PAS anomaly through rearrangement of αVβ3 integrin expression, but CD9 is not primarily involved in PAS development and modulation of αVβ3 integrin. Key words: Placenta Accreta Spectrum (PAS), Trophoblast Invasion, αVβ3-Integrin, CD9, Placental Implantation Disorders