PLATELET-DERIVED GROWTH-FACTOR

Platelet-derived growth factor (PDGF) is a potent activator for cells of mesenchymal origin. Two different PDGF chains termed A and B encode d by different genes have been identified leading to three different P DGF isoforms, the AA and BE homodimers and the AB heterodimer. All thr ee forms have been observed in vivo and possess biological activity in vitro with the AA homodimer being the poorest cellular mitogen. The a vailability of highly purified recombinant PDGF isoforms was the initi al basis for comparative studies in order to specify the different spe ctra of activity of the various PDGF species. This review is particula rly focused on the AB heterodimer as from the standpoint of heterologo us gene expression, this species is the one with the highest demands c oncerning expression and purification protocols. This explains the fac t that, in comparison to PDGF-BB, only very limited data on the in viv o application of PDGF-AB are available so far.