The localization of the photosensitizer determines the dynamics of the secondary production of hydrogen peroxide in cell cytoplasm and mitochondria.

Photodynamic therapy (PDT) is based on the production of the cytotoxic reactive oxygen species (ROS) by light irradiation of a photosensitizer dye in the presence of molecular oxygen. Along with photochemical ROS production, it becomes evident that PDT induces massive secondary production of ROS which is registered long after the irradiation is completed. We created cell lines of human epidermoid carcinoma with the cytoplasmic and mitochondrial localization of protein sensor HyPer sensitive to hydrogen peroxide to compare its concentration in two cellular compartments.

Monitoring of hydrogen peroxide production under photodynamic treatment using protein sensor HyPer.

An interest to HO accumulation under photodynamic treatment can be explained by its participation in intracellular signal cascades. It is important not only to detect HO generation, but also to trace the dynamics of its intracellular content. In the present study the dynamics of cellular HO content under photodynamic treatment was analyzed using genetically encoded reversible HO-sensitive sensor HyPer.