Hepatic long-term factor VIII expression in haemophilic A mice after amniotic stem cells transplant.

Résumé

Introduction: Mesenchymal stem cells have the capacity to expressFactor VIII (FVIII). Recently, it has been demonstrated that humanfetal mesenchymal stem cells are also able to produce von Willebrandfactor (vWF) and present tolerance and low immunogenicity. Our objective was to evaluate the murine amniotic membrane fetal stem cells(mAMSCs) transplant from healthy subjects into immunocompetenthemophilia A (HA) mice and its effect on the hepatic expression ofFVIII.Methods: The mAMSCs were isolated from C57BL/6 GFP+ pregnantmice. The expression of FVIII and vWF in the cultured cells was analyzed by RT-PCR, qPCR and immunofluorescence. mAMSCs GFP+were transplanted intraportally (n = 38) and intraperitoneally (n = 37)in HA mice. The animals were sacrificed after 1, 2, 4 and 8 weeks,and after 6 and 12 months. The expression of FVIII light chain in thetransplanted livers was studied by RT-PCR, and the localization andpresence of the cells and FVIII in the hepatic tissue by immunofluorescence and confocal microscopy.Results: mAMSCs GFP+ showed a positive expression of FVIII andvWF at mRNA and protein levels. FVIII mRNA expression in the transplanted livers was observed in the 40% of the intraportally infusedmice since week 2 to 1 year post-transplant. The intraperitoneal infusion shows a 50% positive mice at 6 months, but none at 1 year. Inthe studied transplanted livers it was possible to find the presence ofGFP+ cells and FVIII expression around the liver sinusoids even 1 yearafter the intraportal infusion and 6 months after the intraperitonealtransplant.Discussion/Conclusion: The allogeneic transplant in immunocompetent HA mice results in the survival of the FVIII+ mAMSCs even 1 year after the intraportal infusion and 6 months after intraperitoneal infusion. More broadly, our results suggest that mAMSCsrepresent a potential source of FVIII interesting for the treatmentof Hemophilia A disease. This project was sponsored by SenecaFoundation of Murcia (15409/PI/10) and Carlos III Institute of Health(PI 10/0270).