Authors

Liang Wang1, Juan Li1, Jie Ding1, Xiaodong He2, *, Lingyi Zhang1, *


Departments

1Department of Division of Liver Disease, Lanzhou University Second Hospital, Lanzhou, PR China - 2Department of General Surgery, Lanzhou University Second Hospital, Lanzhou, PR China

Abstract

Objective: To investigate the relationship between cyclooxygenase-2 (COX-2) and nuclear factor-related factor-2 (NF-2) in liver tissue and the degree of inflammation in (NAFLD) rats with nonalcoholic fatty liver disease. 

Methods: Fifty adult rats were randomly divided into experimental group (n=30), control group (n=10) and Aspirin intervention group (n=10). The experimental group was divided into a five- week experimental group, 10-week experimental group and a 15-week experimental group according to the prolongation of feeding time. The rats in the experimental group were fed with high fat emulsion, while those in the control group were given normal saline and free access to common feed and drinking water. The Aspirin intervention group was given Aspirin at10Mg/100g via intragastrical feeding with high fat emulsion. The body weight, liver size, shape, texture, liver index and liver tissue of rats in each group were measured. The degree of liver inflammation was observed by HE staining. The stage of inflammation was judged according to the diagnostic criteria of histology. At the same time, the expression of cyclooxygenase-2 (COX-2) and nuclear factor-related factor-2 (Nrf-2) were detected by monoclonal antibodies, and the correlation with the inflammatory process was analysed. 

Results: The physical weight of each group from large to small was 15 weeks in the experimental group, Aspirin intervention group, 10 weeks in the experimental group and five weeks in the experimental group. The difference was statistically significant (P<0.05), and the liver wet weight and LI from large to small were 15 weeks in the experimental group, Aspirin intervention group, 10 weeks in the experimental group, five weeks in the experimental group, the control group and the difference was again statistically significant (P<0.05). In the control group, COX-2 and Nrf-2 were weakly positive in the cytoplasm and capsule of very few hepatocytes. COX-2 and Nrf-2 appeared in the cytoplasm of the damaged hepatocytes in the experimental group at five weeks, the positive cells in the experimental group increased again, the positive cells in the damaged cells were moderately positive in the 10 groups and the positive cells in the Aspirin intervention group were diffusible. They were higher than those in the experimental group at 10 weeks. At the 15th week, the expression of COX-2 and Nrf-2 in the experimental group was the strongest, followed by the Aspirin intervention group, followed by the experimental group at the 10th week, the experimental group at the fifth week, and the control group with the weakest expression of COX-2 and Nrf-2. The difference was statistically significant (P<0.05). In the control group, the hepatic lobule structure of the normal liver tissue of the male rats was normal, and the morphology of the hepatocytes was normal; the liver cells of the experimental group were mostly fatty lesions, which were the simple fatty lesions and the liver cells of the experimental group. The experimental group and the Aspirin intervention group were more than four points, which was in accordance with the judgment of NASH. The liver cells of the experimental group and the Aspirin intervention group were more than four points at the 10th week, the 15th week of the experimental group and the control group. At 15 weeks, the hepatocytes of the experimental group were diffusely adipose; the cells were enlarged and varied in size. They were also accompanied by balloon transformation of hepatocytes and infiltration of inflammatory cells in the lobule. 

Conclusion: The expression of COX-2 and Nrf-2 in the liver tissue of rats with alcoholic fatty liver disease reflects the inflammatory process of liver tissue to a certain extent, and it is of great clinical significance to evaluate the inflammatory process of liver tissue. 

Keywords

Nonalcoholic fatty liver disease, COX-2, Nrf-2, inflammatory process.

DOI:

10.19193/0393-6384_2020_3_255