Recombinant erythropoietin (rEpo) is an effective treatment for infants with anemia of prematurity, and is used increasingly as an alternative to multiple transfusions. The primary known function of Epo is to promote erythropoiesis by stimulating the proliferation and differentiation of erythroid progenitor cells, however, animal studies have demonstrated the presence of Epo and its receptor (Epo-R) within the developing murine central nervous system. Our objective was to determine whether mRNA for Epo and Epo-R are expressed in the central nervous system of early and mid-trimester human fetuses. Spinal cords (n=12) and brain (n=6) were collected from human abortuses ranging in maturity from 5 weeks to 24 weeks gestation. Meninges were removed from spinal cords, and total RNA was extracted from washed specimens. The presence of Epo and Epo-R mRNA was determined by reverse transcription followed by polymerase chain reaction using primers designed to differentiate between genomic DNA and mRNA amplification. All fetal spinal cords and brain tested contained Epo-R mRNA. Immunofluorescent staining of spinal cord identified cells expressing Epo-R to be radiating from the ependymal canal toward the anterior and posterior median sulci. Expression of Epo mRNA was also present in both spinal cord and brain samples ranging in age from 5 to 24 weeks gestation. We conclude that Epo and its receptor are expressed in cells of the developing human central nervous system. As the role of Epo within the developing central nervous system is unclear, further studies are needed to determine the long-term neurodevelopmental effects of therapeutic rEpo administered to preterm infants.
