Abstract
Reactive oxygen species (ROS) can irreversibly damage biological molecules, a process known as oxidative stress. Elevated ROS levels are associated with immune cell activation. Sustained immune system activation can affect many different cells in the environment. One cell type that has been detected in almost all tissues of the body is mesenchymal stem/stromal cells (MSC). MSC possess proliferation and differentiation potential, thus facilitating regeneration processes. However, the regenerative capacity of MSC might be impaired by oxidative stress, and the effects of long-term oxidative stress on MSC functions are sparsely described. The examination of oxidative stress is often performed by exposure to H2O2. Since H2O2 is rapidly degraded, we additionally exposed the cell cultures to glucose oxidase (GOx), resulting in sustained exposure to H2O2. Using these model systems, we have focused on the effects of short- and long-term oxidative stress on viability, migration, differentiation, and signaling. All cellular functions examined were affected by the applied oxidative stress. The differences that occur between pulsed and sustained oxidative stress indicated higher oxidative stress in MSC upon direct H2O2 exposure, whereas the GOx-induced prolonged exposure to H2O2 seems to allow for better cellular adaptation. The mechanisms underlying these different responses are currently unknown.