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

ANTONIO PEREZ PEREZ; CASALE, ROBERTO; VARONE, CECILIA L.; JAIME, MARIANA; DUEÑAS, JOSÉ LUIS; MAYMÓ, JULIETA L.; RIEDEL, RODRIGO; PAROLINI, ORNELLA; VICTOR SANCHEZ MARGALET

Buenos Aires

Congreso; International Federation of Placenta Associations (IFPA) Meeting 2019; 2019

INTRODUCTION/OBJECTIVES: The placenta and fetal membranes have recently been proposed as an important stem cells source for regenerative medicine. Gestational cells offer considerable advantages over other stem cells. Amniotic epithelial cells (hAECs) can be isolated from the amnion of the human placenta at term. They express embryonic stem cells markers and they are pluripotent. These characteristics would make hAECs ideal candidates for application in regenerative medicine. Hepatic failure is one of the major causes of morbidity and mortality worldwide and the available treatments have several obstacles. Stem cells have been spotlighted as alternative sources of hepatocytes because of their potential for hepatogenic differentiation. The adequate regulation of the signalling pathways activated during a differentiation process is the key for the success of such process. The signalling pathways involved in hepatic differentiation of hAECs remain poorly understood. We have recently demonstrated that the MAPK pathway is involved in hepatic differentiation of hAECs. The aim of this work was to study some of the main pathways activated in hAECs during their early and late hepatic differentiation process.METHODS: Hepatic differentiation (HD) was assayed by specific HD medium (EGF + dexamethasone). Immunofluorescence, Western blot, qRT-PCR and MTT assays were performed.RESULTS: We have found that HD medium significantly induced an increment in Wnt-1 and B-catenin expression in hAECs, measured by qRTPCR, Western blot and immunofluorescence (IF). Treatment of hAECs with XAV939 (a b-catenin inhibitor) caused the inhibition of HD, as albumin expression was reduced. In addition, we determined that inhibition of B-catenin pathway diminished Ki-67 expression and cell viability, in differentiated hAECs. We have also observed that HD medium promotes phosphorylation of PI3K and Akt, as determined by Western blot and IF. We observed a significant increment in nuclear localization of P-Akt during hAECs HD, related to its antiapoptotic action.CONCLUSION: These results suggest that the activation of the b-catenin and PI3K pathways may be responsible for a successful hepatic differentiation and proliferation of hAECs. Understanding the molecular mechanisms regulating hepatocyte differentiation will significantly facilitate the development of stem cell-based therapy to treat liver diseases.