Exacerbation of coagulation and cardiac injury in rats with cisplatin-induced nephrotoxicity following intratracheal instillation of cerium oxide nanoparticles

Background/Aims: Exposure to particulate air pollution is associated with increased cardiovascular morbidity and mortality. These effects are particularly aggravated in patients with pre-existing kidney diseases. Cerium oxide nanoparticles (CNPs), used as diesel fuel additives, are emitted in vehicle exhaust and affect humans when inhaled. However, thrombotic and cardiac injury resulting from pulmonary exposure to CNPs in experimental acute kidney injury (AKI) is not fully understood. The objective of the present study was to evaluate the thrombotic and cardiac injury effects of CNPs in a rat model of AKI. Methods: AKI was induced in rats by a single intraperitoneal injection of cisplatin (CDDP, 6 mg/kg). Six days after injection, rats were intratracheally (i.t.) instilled with either CNPs (1 mg/kg) or saline (control), and various cardiovascular variables and markers of inflammation, oxidative stress and DNA injury were assessed by enzyme linked immunosorbent assay, colorimetric assay, single-cell gel electrophoresis assay and immunohistochemistry, the following day. Results: Compared with individual CDDP or CNPs treatments, the combined CDDP + CNPs treatment elevated significantly the coagulation function, relative heart weight, and troponin I, lactate dehydrogenase, interleukin-6 (IL-6), tumor necrosis factor α (TNFα), and total nitric oxide levels in the plasma. In heart homogenates, the combination of CDDP and CNPs induced a significant increase in IL-6, TNFα, catalase, and glutathione. Furthermore, significantly more DNA damage was observed in this group than in the CDDP or CNPs groups. Immunohistochemical analysis of the heart revealed that expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) and glutathione peroxidase by cardiac myocytes and endothelial cells was increased in the CDDP + CNPs group more than in either CDDP or CNPs group. Conclusion: I.t. administration of CNPs in rats with AKI exacerbated systemic inflammation, oxidative stress, and coagulation events. It also aggravated cardiac inflammation, DNA damage, and Nrf2 expression.