Erythropoietin gene expression in different areas of the developing human central nervous system

Evidence from cell culture and animal experiments suggests a neuroprotectiv e and neurotrophic function of erythropoietin (EPO). We have quantitated th e distribution of EPO mRNA expression in the developing human central nervo us system (CNS). Patients and Methods: Up to seven biopsies from different areas of the CNS of four preterm fetuses (gestational age 23-37 weeks) were obtained at routine postmortem examinations. EPO mRNA was quantitated by c ompetitive PCR in samples from the CNS, the kidneys, and the liver where th e EPO gene is predominantly expressed at this gestational age. Results: EPO mRNA was most abundant in one sample from the cerebellum (0.29 amol/mug to tal RNA [amol=10(-18)mol]) and two from the pituitary gland (0.23 amol/mug total RNA), but levels varied considerably. EPO mRNA in the cortex cerebri (median 0.12 amol/mug total RNA; n=4) dominated over the expression in the corpora amygdala (median 0.05 amol/mug total RNA: n=4), the hippocampus (me dian 0.03 amol/mug total RNA: n=4), or the basal ganglia (median 0.01 amol/ mug total RNA; n=3). Only little EPO mRNA (<0.01 and 0.06 amol/<mu>g total RNA) was found in the spinal cord. EPO mRNA levels in the cerebellum, pitui tary gland, or the cerebral cortex were within the same range as in the liv er (0.03-1.67 amol/mug total RNA; n=4), or the kidneys (0.06-0.79 amol/mug total RNA; n=4). Conclusion: We found the EPO gene expressed throughout the fetal human CNS. Our data provide the basis to discuss a function for EPO in the brain of humans as well. (C) 2000 Elsevier Science B.V. All rights r eserved.