CEREBROSPINAL-FLUID OF NEWBORN-INFANTS CONTAINS A DEGLYCOSYLATED FORMOF THE INTERMEDIATE FILAMENT NESTIN

Nestin is an intermediate filament protein found in CNS progenitor cel ls. Nestin reappears in CNS tumor cells and reactive astrocytes after CNS injury. In this study we investigated whether nestin could be dete cted in the cerebrospinal fluid (CSF) of newborn infants and whether e xpression levels change with gestational age (GA) and/or brain injury. Using Western blot analysis, we examined the expression of nestin in the CSF of newborn infants (GA 25-42 wk) with asphyxia (n = 14), periv entricular leukomalacia and peri(intra)ventricular hemorrhage (n = 7), and in a control group (n = 11). Protein extract from the periventric ular brain tissue of a 1-wk-old infant was also analyzed. Nestin was d etected in all the CSF samples and in the protein extract from the per iventricular brain tissue. Although the CSF levels of nestin expressio n did not change with increasing GA, the asphyxia group had significan tly lower levels of nestin in the CSF. An unexpected finding was that brain-derived nestin had an apparent molecular mass of approximately 2 40 kD, whereas all analyzed CSF samples contained two nestin-immunorea ctive proteins at 200 and 220 kD. Experimental deglycosylation of the 240-kD form reduced the molecular mass to 220 kD, indicating that nest in undergoes a specific deglycosylation upon release into the CSF.