The esophageal expression of fibrotic cytokines and NADPH oxidase in stress induced esophageal fibrosis and its significance / 中国医师杂志

ABSTRACT

Objective To detect the expression levels of collagen1 (colla-1),transforming growth factor-β1 (TGF-β1),a-smooth muscle actin (α-SMA) and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX-4) in mouse esophagus submitted to chronic restraint stress (CRS),in order to discuss stress-induced esophageal fibrosis and the role of oxidative stress.Methods 20 male Kunming mice were randomly divided into two groups,CRS and normal control (NC).The mice in CRS group were submitted to 2 h per day of restraint stress using home-made device for a period of 14 days,and the mice in both group were treated the same at rest of the time.Fibrotic changes of esophageal tissue were observed using Masson staining.The expression levels of NOX-4 and related fibrotic cytokines in esophageal tissues were detected by several methods such as immunohistochemistry,enzyme-linked immunosorbent assay (ELISA) and realtime polymerase chain reaction (qRT-PCR).Results Body weight in CRS group was significantly lower than NC group (8.75 ± 1.69 vs 12.69 ± 3.16),with statistically significant difference (t =3.11,P ＜ 0.05).Masson staining revealed that CRS mice showed distinct fibrosis of epithelial interstitium,while there was no distinct changes observed in NC mice.Immunohistochemical staining revealed intense staining for NOX-4 in epithelial,mucosal and submucosal layers of esophagi in CRS mice.ELISA showed that the serum level of NOX-4 in CRS mice was higher than NC mice (1.442 ± 0.05 vs 0.449 ± 0.08),with statistically significant difference (t =-27.32,P ＜ 0.01).Real-time PCR results showed that the expression of colla-1,TGF-β1,α-SMA and NOX-4 in CRS mice were as (2.443 ±0.36,2.78 ±0.13,2.244 ±0.18,2.448 ±0.440) times higher than NC mice,with statistically significant difference (t =-11.19,-38.86,-19.90,-10.37,P ＜ 0.01).Conclusions Fibrotic cytokines such as colla-1,TGF-β1 and α-SMA may participate in formation of stress induced esophageal fibrosis,and oxidative stress may play crucial role in the process of esophageal fibrosis.