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BioMed Research International
Volume 2013, Article ID 190178, 8 pages
Research Article

Analysis of Pregnancy-Associated Plasma Protein A Production in Human Adult Cardiac Progenitor Cells

1Department of Gynaecology, Obstetrics and Urologic Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
2Department of Molecular Medicine, Cenci Bolognetti Foundation, Pasteur Institute, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
3Department of Medical Surgical Sciences and Biotechnology, Sapienza University of Rome, Corso della Repubblica 79, 04100 Latina, Italy
4Department of Cardiocirculatory Pathophysiology, Anesthesiology and General Surgery, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy

Received 29 April 2013; Revised 9 September 2013; Accepted 10 September 2013

Academic Editor: Sergiy Sukhanov

Copyright © 2013 Piera D’Elia et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


IGF-binding proteins (IGFBPs) and their proteases regulate IGFs bioavailability in multiple tissues. Pregnancy-associated plasma protein A (PAPP-A) is a protease acting by cleaving IGFBP2, 4, and 5, regulating local bioavailability of IGFs. We have previously shown that IGFs and IGFBPs are produced by human adult cardiac progenitor cells (haCPCs) and that IGF-1 exerts paracrine therapeutic effects in cardiac cell therapy with CPCs. Using immunofluorescence and enzyme immunoassays, we firstly report that PAPP-A is produced and secreted in surprisingly high amounts by haCPCs. In particular, the homodimeric, enzymatically active, PAPP-A is secreted in relevant concentrations in haCPC-conditioned media, while the enzymatically inactive PAPPA/proMBP complex is not detectable in the same media. Furthermore, we show that both homodimeric PAPP-A and proMBP can be detected as cell associated, suggesting that the previously described complex formation at the cell surface does not occur easily, thus positively affecting IGF signalling. Therefore, our results strongly support the importance of PAPP-A for the IGFs/IGFBPs/PAPP-A axis in CPCs biology.