Genotoxic Stress is a Trigger of Endothelial Dysfunction in Wistar Rats: Results of a Molecular Genetic Study

Atherosclerosis and coronary artery disease are the leading causes of disability and mortality among the population. Genotoxic stress can be considered as a new trigger of endothelial dysfunction underlying the pathogenesis of these diseases. This research was aimed to the study of molecular genetic markers of endothelial dysfunction associated with genotoxic stress in normolipidemic Wistar rats. Male Wistar rats that received tail vein injections of the alkylating mutagen mitomycin C (MMC) at the dosage of 0.5 mg/kg body weight (experimental group) or 0.9% NaCl solution (control group) three times a week for a month were included in the presented study. Genotoxic stress in animals was assessed using a micronucleus assay in polychromatophilic erythrocytes (PCE); endothelial dysfunction was identified by assessing the expression of the Vcam1, Icam1, Sele, Selp, Il6, Ccl2, Cxcl1, Mif, Vwf, Serpine1, Plau, Plat, Klf2, Klf4, Nfe2l2, Nos3, Snai1, Snai2, Twist1, Zeb1, Cdh5 and Cdh2 genes in the endothelial monolayer of the descending aorta. It was found that rats from the experimental group are characterized by pronounced genotoxic stress, as evidenced by a more than threefold increased frequency of micronucleated PCE and a decreased proportion of PCE in the total pool of analyzed erythrocytes. Gene expression profiling showed that rats included in the experimental group are characterized by pro-inflammatory activation of endothelium, accompanied by increased expression of the Vcam1, Icam1, Selp, Il6, Ccl2 and Cxcl1 genes, as well as impaired endothelial mechanotransduction, characterized by decreased expression of the Klf2 and Klf4 genes. Thus, MMC-induced genotoxic stress in normolipidemic Wistar rats is associated with impaired two key links of the pathogenesis of endothelial dysfunction and can be considered as one of its triggers.