title: A Method to Monitor Lysosomal Membrane Permeabilization by Immunocytochemistry.
abstract: Programmed cell death involving lysosomal membrane permeabilization (LMP) is a common phenomenon--more the rule than the exception under various cytotoxic stimuli and stressful cellular conditions. The protocol presented here is based on immunocytochemical staining of cathepsin B or L to visualize translocation from the lysosomal lumen to the cytosol. In healthy cells, cathepsins appear in localized punctate structures representing intact lysosomes, whereas LMP results in a diffuse staining pattern throughout the cytoplasm. LMP can be triggered upstream, downstream, or independently of the classical apoptotic death pathway involving mitochondrial outer membrane permeabilization (MOMP). Co-staining with antibodies recognizing the active form of Bax allows investigation of the order of events between LMP and MOMP in death signaling.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Rigshospitalet University Hospital, DK-2100 Copenhagen, Denmark; Unit for Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark.
authors.forename: Line
authors.initials: L
authors.lastname: Groth-Pedersen
authors.affiliation: Unit for Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark.
authors.forename: Marja
authors.initials: M
authors.lastname: Jäättelä
authors.affiliation: Unit for Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Nylandsted
mesh_terms: D000818:Animals; D002401:Cathepsin B / Q000032:analysis*; D056668:Cathepsin L / Q000032:analysis*; D002460:Cell Line; D003600:Cytosol / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D007425:Intracellular Membranes / Q000502:physiology*; D008247:Lysosomes / Q000201:enzymology*; D010539:Permeability
chemical_list: D002401:Cathepsin B; D056668:Cathepsin L