Reorganization of cytoskeleton induced by 5-aminolevulinic acid-mediated photodynamic therapy and its correlation with mitochondrial dysfunction.

Background and Objectives This study investigated the early cellular events which occurred after mitochondrial photodamage induced by 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT). Study Design/Materials and Methods Subcellular localization of protoporphyrin IX (PpIX) in NIH3T3 cells was studied by confocal microscopy. Mitochondrial damage was assessed by measuring mitochondrial transmembrane potential and ATP contents, and confirmed by characteristic appearance on transmission electron microscopy. Cellular adhesion was measured by the level of resistance to trypsinization. Cytoskeletal studies were performed by fluorescent staining of cytoskeletal components. Results Following ALA-PDT, mitochondrial damage was found in NIH3T3 cells as judged by the decrease of membrane potential and ATP contents. Mitochondrial photodamage was futher confirmed by electron microscopy. Resistance to trypsinization after ALA-PDT was shown to be light dose-dependent. The increase of cellular adhesion after ALA-PDT was correlated with mitochondrial photodamage and reorganization of cytoskeletal components in NIH3T3 cells. Conclusions This study has demonstrated that mitochondrial dysfunctions induced by ALA-PDT results in alterations of cellular morphology and cellular adhesion. Lasers Surg. Med. © 2005 Wiley-Liss, Inc.