Influência do desequilíbrio redox e resposta inflamatória na fibrose pulmonar associada a estímulo inflamatório prévio

Abstract

Pulmonary fibrosis (PF) is a chronic lung disease characterized by excessive accumulation of extracellular matrix (ECM) and remodeling in the lung architecture. Although it is already known the role of oxidative stress and inflammation in the isolated pulmonary fibrosis, it is important to observe how it behaves oxidative stress in pulmonary fibrosis when it occurs associated with an underlying disease. The present study aimed to investigate the inflammatory status and oxidative pulmonary fibrosis associated with pulmonary emphysema prior. C57BL / 6 mice were divided into three groups: control group (n = 5) who received intranasal saline (50µl) and were sacrificed at 21 days, bleomycin (BLEO) group (n=15) who received intratracheal bleomycin (0.1U/animal) in the day 0 and were sacrificed at 7 (n=5), 14 (n=5) and 21 (n=5) days and the PPE + BLEO group (n=21) received elastase (PPE)(3U/animals) and 14 days after receiving bleomycin and were sacrificed at 14 (n = 7), 21 (n = 7) 28 ° (n = 7) and 35 (n = 7) days. Histological analysis was achieved using H&E and Sirius red staining; biochemical analysis for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) and ELISA for IL-1β and IL-6 were conducted. Pulmonary fibrosis occurred from day 14 (p<0.001) emphysema and pulmonary fibrosis from day 28 (p <0.001) and occurred an increase of collagen fibers in the BLEO group 21days (p<0.001) and PPE + BLEO 21days (p <0.001). Antioxidant enzymes CAT (p <0.01), SOD (p <0.01), and GPx (p <0.01) were reduced and GST increased in the BLEO group 21 days (p<0,05). In the PPE + BLEO group 21 days occurred an decreased antioxidant enzymes CAT, SOD, GPx (p <0.05), and GST. Oxide levels were higher in the BLEO groups 21 days (p <0.01), and PPE + BLEO group 21 days (p <0:01). IL-1β was elevated in the group BLEO 7 days when compared to control (p <0.001) and the PPE + BLEO group 7 days (p<0.01). The inflammatory response inhibited the action of the antioxidant system contributes to the aggravation of the injury. This suggests that anti-inflammatory therapies may contribute to reducing the inflammatory response as indirectly to the antioxidant system.