Interleukin-1 promotes expression and phosphorylation of neurofilament andtau proteins in vivo

Slow-release, IL-1-impregnated pellets implanted in rat cerebral cortex to simulate chronic overexpression of IL-1 significantly increased relative ti ssue levels of tau mRNA and of tau immunoreactivity in neuronal cell bodies and in swollen dystrophic neurites that also overexpressed phosphorylated and nonphosphorylated neurofilament epitopes. in addition, rats with IL-1-i mpregnated pellets, but not control rats or those with sham pellets, showed focal immunoreactivity for hyperphosphorylated tau epitopes present in pai red helical filaments. Our results are consistent with an important driving role for IL-1 in the pathogenesis of Alzheimer-type neuronal and neuritic changes. (C) 2000 Academic Press.