Molecular and immunological changes in blood of rats exposed to various doses of asbestos dust

Asbestos-related diseases are a group of diseases resulting from the inhalation of asbestos fibres and their subsequent deposition in the lung parenchyma, which causes the development of inflammatory and fibrotic processes in the respiratory system. Cases of the disease often occur in the practice of doctors.The purpose of the study was to examine the level of circulating-free mitochondrial DNA (cf mtDNA), pro-inflammatory cytokines, immunological status and structural changes in the lung of rats exposed to various doses of asbestos dust.Immune monitoring was performed using the peripheral blood samples of 40 male Wistar rats exposed and unexposed to asbestos dust. cf mtDNA copy numbers were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and cytokines were determined using a rat Enzyme Linked Immuno Sorbent Assay (ELISA) kit.A comprehensive assessment of the histopathological study performed under exposure to asbestos at a dose of 25 mg and 50 mg showed the presence of pronounced structural defects in the lung tissue of laboratory rats. The level of cf mtDNA in plasma of rats exposed to asbestos at a dose of 25 mg was reliably higher than that of control rats, and animals exposed to asbestos at a dose of 50 mg. The highest levels of pro-inflammatory cytokines IL-6 and TNF-a were also observed after asbestos dusting at a dose of 25 mg.According to the results of the immunological status obtained, the decrease in the levels of pro-inflammatory cytokines in the blood plasma at 50 mg is due to the immunosuppressive effect in the rat immune system at this dose. A positive correlation was found between TNF-a level and copy numbers of cf mtDNA at a dose of 25 mg.