H2A.X Phosphorylation in Oxidative Stress and Risk Assessment in Plasma Medicine

Figure 4

Obstacles of exogenously (cold plasma-generated) short-lived reactive to species from the extracellular to the nuclear compartment. The plasma jet generates ROS/RNS in the liquid phase around the biological system cell ①. Plasma-liquid interactions and components of the antioxidant system are active in the extracellular space. In addition to diffusion, aquaporins enable the limited ROS/RNS passage, especially H₂O₂, across the cell membrane ②. Cholesterol-dependent lipid peroxidation by radicals may facilitate transmembrane diffusion through pore formation. Cold plasma exposure may increase the cytosolic ROS/RNS levels exposing the cell to oxidative stress, which the intracellular antioxidant system, including catalase, glutathione, NADPH+H⁺, and peroxiredoxins, attempts to counteract ③. Intracellularly, ROS/RNS would have to pass through several structures and membranes of cell organelles, e.g., the ER, to eventually reach the nucleus ④. Finally, intranuclear antioxidant systems also offer protection from oxidative damage ⑤.