Interleukin-1 beta and tumor necrosis factor-alpha synergistically stimulate nerve growth factor (NGF) release from cultured rat astrocytes.

Nerve growth factor (NGF) may mediate responses to brain injury. To examine regulation of NGF gene expression with respect to neural trauma we examined the effects of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) on NGF production in cultures of rat astroglial cells. Purified neocortical astrocytes in serum-free medium were treated with IL-1 beta, TNF-alpha or both. Whereas IL-1 beta and TNF-alpha alone elicited only small effects, simultaneous addition elicited within 48 h a large (3- to 6-fold) increase in NGF content in culture supernatants. Our data are consistent with a role for cytokines in NGF synthesis and release in the injured central nervous system (CNS).