WATCH FOR ICE IN NEURODEGENERATION

Neuronal death occurs naturally during brain development and is a comm on response to an external insult. Cell death, whose mechanisms are cu rrently being elucidated, appears in three forms: necrosis, apoptosis and programmed cell death, Recently, attention has focused on a family of cysteine proteases whose prototype is interleukin-1 beta convertin g enzyme (ICE), ICE, essential for IL-1 beta production and, thus, cri tical to necrotic mechanisms, also plays a role in apoptosis mediated through the stimulation of the lymphocyte fas antigen, The absence of ICE expression in neurons makes ICE an unlikely direct participant in neuronal death, However, the existence of ICE family members in neuron s combined with the pharmacological inhibition of both apoptosis in vi tro and programmed cell death during development make ICE homologs can didates for mediating these two forms of cell death, Since several neu rodegenerative diseases as well as at least one neurological disorder may have an apoptotic component, antagonists of this protease family m ay be neuroprotective.