Mechanism study of Tnfaip3 gene affecting colitis in mice via regulating mitochondria
10.3760/cma.j.cn101480-20231030-00052
- VernacularTitle:Tnfaip3基因通过调控线粒体影响结肠炎小鼠的机制研究
- Author:
Jiaxin XU
1
;
Meiping YU
1
;
Haoying LIU
1
;
Yu CHEN
1
;
Fang XIAO
1
Author Information
1. 华中科技大学同济医学院附属同济医院消化内科，430030 武汉
- Publication Type:Journal Article
- Keywords:
Inflammatory bowel disease;
Gene, Tnfaip3;
Oxidative stress;
Mitochondria damage;
Mitophagy
- From:
Chinese Journal of Inflammatory Bowel Diseases
2024;08(5):395-402
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the mechanism of tumor necrosis factor alpha-induced protein 3 ( Tnfaip3) gene affecting the intestinal inflammation in mice with dextran sulfate sodium (DSS) -induced colitis by regulating mitochondria. Methods:Female Tnfaip3 heterozygous deficiency ( Tnfaip3 +/-) mice ( n = 14) and wild-type (WT) mice ( n = 14) were collected and divided into 4 groups including wild type (WT) group, colitis model (WT-DSS) group, Tnfaip3 heterozygous deficiency ( Tnfaip3 +/-) group, Tnfaip3 heterozygous deficiency colitis model ( Tnfaip3 +/--DSS) group, with 7 mice in each group. Mice colitis in WT-DSS and Tnfaip3 +/--DSS groups were induced by drinking 3% DSS water for 7 days, while mice in WT and Tnfaip3 +/- groups were treated with tap water. Body weight and disease activity index (DAI) were evaluated daily. The mice were sacrificed after 7 days of modeling, the colon length was measured, the colon tissue damage was observed under the microscope, and the colon histopathological score was evaluated. The mRNA expressions of inflammatory factors as tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and nuclear factor κB (NF-κB) in colon tissue were detected by quantitative real-time PCR. Oxidative stress indicators such as malonic dialdehyde (MDA), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in colon tissue were detected. Transmission electron microscopy was used to observe the structures of mitochondria, lysosomes, and autophagic mitochondria, and calculate the numbers. Mitochondrial membrane potential JC-1 and adenosine-triphosphate (ATP) levels were detected, and Western blot was used to detect the expressions of mitophagy-related proteins PINK1, P62, and LC3B Ⅱ/LC3B Ⅰ in mitochondria and cytoplasm. Results:The survival rate of mice in all groups was 100%. Compared with WT group, the mice in Tnfaip3 +/- group had lower body weight, shorter colon and higher histopathological scores (all P < 0.05). Compared with WT-DSS group, the mice in Tnfaip3 +/--DSS group had lower body weight, higher DAI score, shorter colon, higher histopathological score, and higher mRNA expressions of inflammatory factors TNF-α, IL-1β and NF-κB in colon tissues (all P < 0.05). MDA level in colon tissues of Tnfaip3 +/- mice was higher than that of WT mice ( P < 0.05). Compared with WT-DSS group, the MDA level in Tnfaip3 +/--DSS group was higher, the levels of T-AOC, GSH-PX and SOD were lower (all P < 0.05). Compared with WT-DSS group, Tnfaip3 +/--DSS mice had more severe intestinal disordered mitochondrial structure, less mitochondrial number, higher mitochondrial membrane potential JC-1 level and lower mitochondrial ATP content, more number of lysosomes and autophagic mitochondria and higher expressions of proteins such as PINK1, P62 and ratio of LC3BⅡ/LC3BⅠ in mitochondria and cytoplasm (all P < 0.05) . Conclusion:Tnfaip3 gene may play a protective role in intestinal inflammation of colitis mice by regulating oxidative stress, mitochondria damage and mitophagy.
