Oxidative stress in the endothelial cell culture exposed to mitomycin C

Abstract

Background. Atherosclerosis is one of the leading cardiovascular pathologies. Evidence suggests that DNA damage caused by endothelial cell exposure to mitomycin C (MMC) leads to endothelial dysfunction and is the risk factor for this disease. MMC is an alkylating mutagen involved in the development of oxidative stress, which is also a risk factor for atherosclerosis. Aim. To access the levels of oxidative stress markers in the primary human endothelial cell culture exposed to alkylating mutagen MMC.Material and Methods. Commercially available primary cultures of endothelial cells obtained from human coronary artery (HCAEC) and human internal thoracic artery (HITAEC) were used in the study. The cells were cultivated in the presence of 500 ng/mL MMC (experimental group) and without mutagenic load (control group). The levels of reactive oxygen species, reactive nitrogen species, and 8-OH-deoxyguanosine (8-OHdG) in cell growth media were assessed by enzyme-linked immunosorbent assay. The relative telomere length and expression of TERT and POT1 genes were accessed in endothelial cells by quantitative polymerase chain reaction. Statistical analysis of data was performed using GraphPad Prism 9 software.Results. There were no diff erences in the concentrations of reactive oxygen species, reactive nitrogen species (NO2 -, NO3 -, NO2 -/NO3 -), and 8-OHdG in HCAEC and HITAEC cultures exposed to MMC compared to the corresponding parameters in the non-exposed controls. At the same time, HCAEC and HITAEC exposed to MMC were characterized by a decrease in the relative telomere length compared to control (10.97 vs. 27.03 in HCAEC, p = 0.002 and 9.12 vs. 25.64 in HITAEC, p = 0.001). Moreover, we discovered 1.75-fold increase in the expression of POT1 gene in the experimental HCAEC compared to control (p = 0.019). No expression of TERT gene was observed in study groups.Conclusions. Alkylating mutagen MMC did not induce any pronounced oxidative stress in the primary human endothelial cells in vitro. The development of endothelial dysfunction caused by MMC exposure was triggered mainly by DNA alkylation resulting in the genotoxic stress in the endothelial cells.