BACKGROUND: The survival promoting peptide Y-P30 has a variety of neuritogenic 
and neuroprotective effects in vitro and in vivo. In previous work we reported 
the expression of Y-P30/dermcidin in maternal peripheral blood mononuclear cells 
(PBMCs) and the transport of the protein to the fetal brain. In this study we 
analyzed hormonal regulation of Y-P30 in human immune cells and expression of 
Y-P30 in the placenta. We further studied the stability and secretion of the 
Y-P30 peptide.
RESULTS: We found indications that Y-P30 might be produced in human placenta. 
The Y-P30 mRNA was rarely found in isolated human PBMCs and alpha-feto-protein, 
human chorionic gonadotropin as well as estradiol combined with progesterone 
could not induce Y-P30 expression. Y-P30 was found to be extraordinarily stable; 
therefore, contamination with the peptide and the Y-P30/Dermcidin precursor mRNA 
is a serious concern in experiments looking at the expression of 
Y-P30/Dermcidin. In cultured cell lines and primary neurons we found that Y-P30 
could be released, but neuronal uptake of Y-P30 was not observed.
CONCLUSIONS: Our data suggest that a source of Y-P30 apart from eccrine glands 
might be the placenta. The peptide can be secreted together with the signaling 
peptide and it might reach the fetal brain where it can exert its neuritogenic 
functions by binding to neuronal membranes.