Ahallmarkofallformsofneurodegenerativediseasesisimpairmentofneuronalfunctions,andinmanycasesneuronalcelldeath.Althoughtheetiologyofneurodegenerativediseasesmaybedistinct,differentdiseasesdisplayasimilarpathogenesis,forexampleabnormalimmunitywithinthecentralnervoussystem(CNS),activationofmacrophage/microgliaandtheinvolvementofproinflammatorycytokines.Recentstudiesshowthatneuronsinaneurodegenerativestateundergoahighlyregulatedprogrammedcelldeath,alsocalledapoptosis.TNF-relatedapoptosis-inducingligand(TRAIL),amemberoftheTNFfamily,hasbeenshowntobeinvolvedinapoptosisduringmanydiseases.Asonememberofadeathligandfamily,TRAILwasoriginallythoughttotargetonlytumorcellsandwasnotpresentinCNS.However,recentdatashowedthatTRAILwasunregulatedinHIV-1-infectedandimmune-activatedmacrophages,amajordiseaseinducingcellduringHIV-1-associateddementia(HAD).TRAILisalsoinducedonneuronbyβ-amyloidprotein,animportantpathogenforAlzheimer'sdisease.Inthisreview,wesummarizethepossiblecommonaspectsthatTRAILinvolvedthoseneurodegenerativediseases,TRAILinducedapoptosissignalingintheCNScells,andspecificroleofTRAILininpidualdiseases.Cellular&MolecularImmunology.2005;2(2):113-122.
