Protective Effects of Human Dermal Fibroblast-Derived Extracellular Vesicles on WI-38 Lung Fibroblasts Under Different Stress Conditions

Abstract

In lung fibroblasts, cellular stress can disrupt tissue homeostasis through the accumulation of reactive oxygen species (ROS), loss of membrane integrity, and apoptotic cell death. In this study, the protective effects of extracellular vesicles (EV) isolated from human fibroblasts by ultracentrifugation were investigated in normal human lung fibroblast Wl-38 cells exposed to three stress models induced by heat, H2O2, and CoCl2. Cells were subjected to heat stress at 42 °C for 1 h, 40 µM H2O2, and 500 µM CoCl2; extracellular vesicles treatment was administered 1 h after the onset of stress, and analyses were performed 24 h later. The extracellular vesicle dose–response was evaluated using the MTT assay; ROS, apoptosis, propidium-iodide (PI) uptake, and miR-21-5p expression were assessed using the relevant methods. All three stress models significantly increased ROS and total apoptosis. Extracellular vesicle treatment reduced ROS levels; reduced total apoptosis from 55.06% to 33.40% under heat stress, from 55.16% to 43.40% under H2O2 stress, and from 54.43% to 32.40% under chemical hypoxia. PI values also decreased significantly in all three models. A significant decrease in miR-21-5p expression was observed in the exosome-treated groups compared to the stress groups. The results suggest that fibroblast-derived extracellular vesicles may exhibit a common cytoprotective phenotype that reduces to various stress stimuli.