Neurotrophic function of conditioned medium from human amniotic epithelial cells.

Human amniotic epithelial cells (HAEC) may have pluripotent function because they are formed from the epiblast cells at the 8th day of fertilization. Previously, we reported that HAEC have the capacity to synthesize and release acetylcholine and catecholamine associated with the binding sites of catecholamine receptors. We show the neurotrophic function of a conditioned medium from HAEC using cultured cortical neurons of E18 rats. Extensive analyses with various techniques demonstrated that HAEC and immortalized HAEC synthesize and release brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and nerve growth factor (NGF). Other neurotrophic factors were not detected in a cultured medium of HAEC by enzyme immunoassay. Various neurotrophic factors or growth factors did not show neurotrophic effects on E18 rat neuron except for EGF. Because EGF was not detected in the conditioned medium of HAEC, these data indicate an unidentified neurotrophic factor presently that is synthesized and released from HAEC. The amniotic membrane may have a significant role in supplying neurotrophic factors to the amniotic fluid as well as neurotransmitters, suggesting an important function to the early stages of neural development in the embryo. Copyright 2000 Wiley-Liss, Inc.