Intracellular photoinduced oxidative stress by zinc phthalocyanine photosensitization: a study of the early events in real time using confocal microscopy

Abstract

Oxidative stress has been implicated in several biological and pathological aspects. Reactive oxygen species (ROS) have been proposed to act as signal transduction molecules activating reactions leading to cell rescue or to cell apoptosis/necrosis. In the present study, oxidative stress was induced by photosensitization of zinc phthalocyanine (ZnPc) in human fibroblasts using a photodynamic dose that did not lead to apoptosis or necrosis. The induction of oxidative stress was performed at the microscope stage in preassigned time. The cascade of phenomena evoked was studied in real time and at the single cell level using confocal laser scanning microscopy. Using specific vital fluorescent probes, alterations induced by oxidative stress in mitochondria membrane potential, in intracellular pH and in calcium concentration were recorded. Image processing and analysis techniques were used to quantify the observed changes. Subcellular localization of the photosensitizer was studied in order to determine the primary and immediate ROS target. It was found that ZnPc is mainly localized in the mitochondria region. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/20/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Proc. of SPIE Vol. 5142 3 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/20/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Proc. of SPIE Vol. 5142 7 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/20/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

Control of actin polymerization via reactive oxygen species generation using light or radiation

“…There are numerous hypotheses on the mechanism of action, however, some propose that it involves the production of ROS. Accordingly, there are numerous reports of ROS production at low levels of light (Alexandratou et al, 2002;Lavi et al, 2003;Chen et al, 2011;George et al, 2018). Kao et al…”