Tumor necrosis factor-α and neuronal development

Tumor necrosis factor-alpha (TNF alpha) is a prototypic inflammatory cytokine up-regulated in most if not all neurodegenerative diseases. Many studies have reported variable roles in the adult or pathological brain. In contrast, the implication of TNF alpha in developmental neuronal cell death has been well documented in few studies. In sympathetic and trigeminal neurons, TNF alpha acts in an autocrine manner to induce immediate cell death on neurotrophic factor deprivation. In the spinal cord, TNF alpha is transiently produced by macrophages and commits motoneurons to become competent to die 2 days later. TNF alpha is also likely to induce immediate and delayed prodeath effects in adult and pathological tissues. Data obtained in embryonic systems will thus help to develop new therapeutic approaches to pathological neuronal death in adults.