Hepatocyte growth factor (HGF), is a growth factor which promotes the survival and migration of immature neurons. HGF is widely expressed in the developing brain. In early stages of embryogenesis, cells within the ependymal lining of neural tube are thought to secrete cerebrospinal fluid (CSF). As the neural tube closes, the choroids plexuses secrete proteins, including growth factors into the CSF. In this study, CSF was aspirated from the cisterna magna of embryonic mice and the relative HGF expression was measured on gestational days 12 to 21 (E12-E21) and postnatal days 1-10 (P1-P10) by Western Blot. The relative CSF HGF expression increased from E12 to E18 and decreased from E19 until birth. After birth there was a rapid increase in HGF expression until day P2, and thereafter the levels decreased from day P4 to day P9. Days E16-E18 and P1-P3 coincide with the onset of neurons and glial migration in the cerebral cortex, respectively. Since CSF is in contact with the cerebral cortical germinal epithelium, changes in the HGF expression may reflect neuroepithelial cell migration. It is concluded that HGF might be involved in cerebral cortical development and it is a constant component of CSF during mouse embryonic development and early postnatal stages.
