Interleukin-1 beta up-regulates expression of neurofilament light in humanneuronal cells

Elevated expression of interleukin-1 (IL-1 beta), a pro-inflammatory cytoki ne secreted by activated microglia, is a pathogenic marker of numerous neur odegenerative processes including Alzheimer's disease (AD). We have charact erized a link between IL-1 beta and the 68-kDa neurofilament light (NF-L) p rotein, which is a major component of the neuronal cytoskeleton. Using huma n brain aggregate cultures, we found that IL-1 beta treatment significantly increased NF-L expression in primary neurons. Analysis of mRNA levels demo nstrated elevated NF-L expression within 72 h while imaging of neurons by i mmunofluorescent staining for NF-L confirmed IL-1 beta -induced NF-L protei n expression. These observations suggest a potential inflammatory-induced m echanism for deregulation of an important cytoskeletal protein, NF-L, possi bly leading to neuronal dysfunction.