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Reversible Effects of Photodamage Directed Toward Mitochondria
Author(s) -
Kessel David
Publication year - 2014
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 - 10.1111/php.12283
Subject(s) - apoptosis , mitochondrion , viability assay , photodynamic therapy , programmed cell death , membrane potential , chemistry , population , photosensitizer , biophysics , cell , microbiology and biotechnology , biology , biochemistry , photochemistry , medicine , environmental health , organic chemistry
When the initial effect of photodynamic therapy ( PDT ) involves mitochondrial photodamage, an early effect is loss of the mitochondrial membrane potential (ΔΨ m ). Using murine hepatoma 1c1c7 cells and a photosensitizing agent known to target mitochondria, we examined loss of ΔΨ m , initiation of apoptosis and loss of viability as a function of time and light dose. There was a correlation between loss of viability and the rapid disappearance of ΔΨ m , as detected by the potential‐sensitive probe Mitotracker Orange ( MTO ). Loss of ΔΨ m was, however, reversible even with a substantial loss of viability. Unless there was a supralethal level of photodamage, 1c1c7 cells recovered their mitochondrial membrane potential, even if the cell population was on the pathway to apoptosis and cell death. These results indicate that when mitochondria are the initial PDT target, a qualitative estimate of photokilling can be provided by assessing the initial loss of ΔΨ m .