EXPRESSION OF THE NEUROFIBROMATOSIS-1 (NF1) GENE IN REACTIVE ASTROCYTES IN-VITRO

NEUROFIBROMIN, the product of the neurofibromatosis 1 (NF1) gene, is a n important tumor suppressor protein expressed most abundantly in the nervous system. Within the central nervous system, neurofibromin has b een localized to neurons and oligodendrocytes but not astrocytes. As i ndividuals with NF1 are at an increased risk for optic pathway gliomas and astrocytomas, we chose to re-evaluate the level of neurofibromin expression in primary cultures of murine cortical astrocytes under con trol and reactive conditions. Astrocytes under control conditions expr essed low levels of NF1 mRNA and protein. Following stimulation with d ibutyryl-cyclic AMP or interferon-gamma in combination with either lip opolysaccharide or interleukin-1 beta, there was a marked increase in NF1 mRNA and protein expression. These results suggest that neurofibro min may be involved in the process of reactive astrocytosis seen in re sponse to CNS injury.