Mixed lineage kinase domain-like (MLKL) is the terminal protein in the pro-inflammatory necroptotic cell death program. RIPK3-mediated phosphorylation is thought to initiate MLKL oligomerization, membrane translocation and membrane disruption[3]. MLKL promotes vascular inflammation by regulating the expression of adhesion molecules ICAM1, VCAM1, and E-selectin in endothelial cells (EC). MLKL deficiency suppresses the expression of these adhesion molecules, thereby reducing EC-leukocyte interaction in vitro and in vivo[4]. MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity. The Mg(2+)-preferred permeability and five transmembrane segment topology distinguish MLKL from previously identified Mg(2+)-permeable channels and thus establish MLKL as a novel class of cation channels[5].Mice deficient in MLKL (Mlkl-/-) had reduced neuronal death (24 h) and BBB permeability at 24 h but not 30d, and improved post-injury rotarod performance vs. WT[6]. MLKL activation is sufficient to induce the processing and release of bioactive IL-1β. MLKL activation triggers potassium efflux and assembly of the NLRP3 inflammasome, which is required for the processing and activity of IL-1β released during necroptosis. Notably, MLKL activation also causes cell membrane disruption, which allows efficient release of IL-1β independently of the recently described pyroptotic effector gasdermin-D[7]. GW806742X, an ATP mimetic and a potent MLKL inhibitor, binds the MLKL pseudokinase domain with a Kd of 9.3 μM. GW806742X has activity against VEGFR2 (IC50=2 nM). GW806742X retards MLKL membrane translocation and inhibits necroptosis[8].
搜索
