Amniotic epithelial stem cells: Signalling pathways activated during their hepatic differentiation and proliferation.

RODRIGO RIEDEL; ANTONIO PÉREZ-PÉREZ; MARIANA JAIME; ORNELLA PAROLINI; ROBERTO CASALE; JOSÉ LUIS DUEÑAS; VICTOR SÁNCHEZ MARGALET; CECILIA VARONE; JULIETA MAYMÓ

Congreso; International Federation of Placenta Associations 2019 (IFPA2019) and 8th Latin American Symposium on Maternal-Fetal Interaction and Placenta (VIII SLIMP); 2019

IFPA

Objectives: The placenta and fetal membranes have recently beenproposed as an important stem cells source for regenerative medicine.Amniotic epithelial cells (hAECs) can be isolated from the amnion ofthe human placenta at term. They express embryonic stem cellsmarkers and they are pluripotent. These characteristics would makehAECs ideal candidates for application in regenerative medicine. Hepatic failure is one of the major causes of morbidity and mortalityworldwide and the available treatments have several obstacles. Stemcells have been spotlighted as alternative sources of hepatocytesbecause of their potential for hepatogenic differentiation. The adequateregulation of the signalling pathways activated during a differentiationprocess is the key for the success of such process. The aim of this workwas to study some of the main pathways activated in hAECs duringtheir hepatic differentiation process.Methods: Hepatic differentiation (HD) was assayed by specific HD medium (EGF + dexamethasone). Immunofluorescence, Western blot, qRTPCR, PAS staining and MTT assays were performed.Results: We have found that HD medium significantly induced anincrement in Wnt-1 and B-catenin expression in hAECs, measured byqRTPCR, Western blot and immunofluorescence (IF). Treatment ofhAECs with XAV939 (a b-catenin inhibitor) caused the inhibition of HD,as albumin expression and glycogen synthesis were reduced. In addition, we determined that inhibition of b-catenin pathway diminishedKi-67 expression and cell viability, during HD. We have also observedthat HD medium promotes phosphorylation of PI3K and Akt, asdetermined by Western blot and IF. We observed a significant increment in nuclear localization of P-Akt during hAECs HD, related to itsantiapoptotic action.Conclusion: These results suggest that the activation of the b-catenin andPI3K pathways may be responsible for a successful hepatic differentiationand proliferation of hAECs. Understanding the molecular mechanismsregulating hepatocyte differentiation will significantly facilitate thedevelopment of stem cell-based therapy to treat liver diseases