Abstract

Background Exposure to particulate matter, partially composed by Polycyclic Aromatic Hydrocarbons (PAHs), has emerged as risk factor for cardiovascular disease. In Chile, Temuco is one of the most affected cities mainly due to the air pollution from burning of wood for heating during the cold season, in which the admissions for acute coronary syndrome are doubled. Have been described that Phenanthrene, Fluorantene and Pyrene are the predominant PAHs in air samples. However, the mechanisms by which these compounds could contribute to increased cardiovascular risk have not been explored. The present study aimed to evaluate the effects of exposure to PAHs on inflammation and endothelial dysfunction markers in a murine model. Methods 20 male Balb/c mice were randomly distributed in four groups of 5 animals each, including a control group (C = without exposure) and three groups exposed to low (L), medium (M) and high levels (H) of a mixture of Phenanthrene, Fluorantene and Pyrene. The exposed groups were subjected during five weeks to the administration of a PAHs solution via nasal instillation. Once the exposure period was over, whole blood samples were obtained to assess serum levels of IL-6, IL-10, IL-17A, INF-γ and TNF-α. Aortic tissue was obtained to quantify the gene expression of ICAM-1, VCAM-1, IL6 and TNF-α using the Real-time Polymerase Chain Reaction (qPCR) technique. LinRegPCR® software was used for qPCR analysis, presenting the difference in the expression relative to the control group of the genes of interest normalized by the reference genes RPL32 and ACTB. Results Significant differences were observed in serum levels of IL6 (C vs. L, p=0.022); C vs. M, p=0.0087) and IFNγ (C vs. L, p=0.01; C vs. M p=0.013), without changes for TNFα (p=0,159), IL10 (p=0,250) and IL17a (p=0,208). Regarding the gene expression analysis, differences in the relative expression were observed for ICAM1 (C vs. H, p=0.049) and VCAM-1 (C vs. H, p<0.0001). Conclusion These results suggest that Phenanthrene, Fluorantene and Pyrene present in the PM, achieve the induction of serum inflammatory markers and endothelial dysfunction associated with the development of cardiovascular disease in the used murine model.