This work was funded by the ERDF through Programa Operacional Factores de Competitividade - COMPETE and by national funds by FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) through grants FCOMP- 01-0124-FEDER-021150 - PTDC/SAU-ENB/119292/2010 attributed to M.G., which included a research fellowship awarded to T.L., and COMPETE funding (Project “Stem cell based platforms for Regenerative and Therapeutic Medicine”, Centro-07-ST24-FEDER-002008). J.B.R acknowledges FCT for grant PTDC/SAUNMC/ 119937/2010 - FCOMP-01-0124-FEDER-021333 and FCT financially supported J.P.F. through fellowship SFRH/BPD/34834/2007. Thanks are also due to FCT/MEC for the financial support to the QOPNA research Unit (FCT UID/QUI/00062/2013), (also through national funds, co-financed by FEDER within the PT2020 Partnership Agreement).