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Determinants of the Apoptotic Response to Lysosomal Photodamage
Author(s) -
Kessel David,
Luo Yu,
Mathieu Patricia,
Reiners John J.
Publication year - 2000
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2000)0710196dotart2.0.co2
Subject(s) - lysosome , cathepsin , caspase , apoptosis , cytochrome c , cathepsin b , cytosol , chemistry , microbiology and biotechnology , cathepsin d , proteases , mitochondrion , biochemistry , cell culture , caspase 2 , biology , enzyme , programmed cell death , genetics
Studies with mouse leukemia L1210 cells revealed that selective lysosomal photodamage caused by any of three photosensitizing agents was followed by a gradual loss of the mitochondrial membrane potential (ΔΨ m ), release of cytochrome c into the cytosol, increased DEVDase activity (a measure of levels of caspase‐3) and a limited apoptotic response. Similar effects were observed in the murine hepatoma 1c1c7 cell line. Immunofluorescence techniques employing 1c1c7 cells demonstrated the immediate release of the lysosomal enzyme cathepsin B following lysosomal photodamage. These studies suggest that the cytotoxic effects of lysosomal photodamage are initiated by released lysosomal proteases that either directly and/or indirectly activate caspases as a consequence of the induction of mitochondrial damage.