Heparin regulates survival and differentiation of mesencephalic progenitors mediated via FGF2 in vitro

Heparin plays an important role in the survival and differentiation of mesencephalic progenitors mediated by FGF-2 in vitro. If the heparin concentration is gradually increased, cell survival mediated by FGF-2 can be greatly enhanced, to a maximum concentration of 20 ng/ml FGF-2 from 5 microg/ml heparin. However, differentiation of FGF-2 responsive mesencephalic progenitors is inhibited by heparin. When cortical, mesencephalic and hippocampal astrocytes were primed with FGF-2 and heparin, the latter two astrocytes promoted the differentiation of TH-positive neurons from mesencephalic progenitors. RT-PCR analysis showed that FGFR1, FGFR2 and FGFR3 were expressed in the cortical astrocytes, but only FGFR1 and FGFR3 were expressed in the mesencephalic and hippocampal astrocytes.