Contribution of reactive oxygen species via the OXR1 signaling pathway in the pathogenesis of monocrotaline-induced pulmonary arterial hypertension: The protective role of Crocin

Pulmonary arterial hypertension (PAH) identified by progressive increase in pulmonary vascular resistance and pressure, ultimately leading to right ventricular failure and sudden death. Oxidation resistance 1 (OXR1) and its downstream target genes has a pivotal role for defense against oxidative stress. But its molecular function is unknown in respiratory system disorders. This study designed to determine whether PAH associated with oxidative stress and OXR1 signaling pathway modulation. Also, Crocin co-treatment evaluated to determine the possible role and mechanism in pulmonary arterial hypertension.The PAH model was induced by a single dose of MCT. It was given intraperitoneal administration of Crocin or saline for 21 consecutive days the other groups in this study. In the last day of experiment, hemodynamic parameter and right ventricular hypertrophy was evaluated as PAH index. The expression levels of OXR1, P21 and Nrf2 genes were detected through RT-PCR. Moreover, oxidative stress index and antioxidant capacity were measured and histological examination were used to determine the lung tissue injuries.Results of the current study demonstrated that the OXR1 and P21 gene expression significantly decrease in PAH which is associated with increase of lipid peroxidation and decrease antioxidant capacity in lung tissue. Crocin co-treatment significantly improved the hemodynamic, oxidative stress biomarkers and histological data of the PAH rats, which associated with increase of OXR1 and its downstream target genes.This report reveals the critical role of OXR1 in pathogenesis of oxidative stress-related pulmonary disease. Current experiment also provides evidence that Crocin has a protective effect against MCT-induced pulmonary arterial hypertension by modulation of OXR1 signaling pathway in rats.