Fibrinogen/AKT/Microfilament Axis Promotes Colitis by Enhancing Vascular Permeability

• Published in: Cellular and molecular gastroenterology and hepatology 2021-01, Vol.11 (3), p.683-696
• Main Authors: Zhang, Chong, Chen, Honglv, He, Qiaoling, Luo, Yiqin, He, Andong, Tao, Ailin, Yan, Jie
• Format: Article
• Language: English
• Subjects: Actin Cytoskeleton - metabolism; Animals; Biopsy; Capillary Permeability - drug effects; Capillary Permeability - immunology; Case-Control Studies; Cell Line; Colitis; Colitis, Ulcerative - chemically induced; Colitis, Ulcerative - immunology; Colitis, Ulcerative - pathology; Colon - blood supply; Colon - immunology; Colon - pathology; Dextran Sulfate - administration & dosage; Dextran Sulfate - toxicity; Disease Models, Animal; Fibrinogen; Fibrinogen - antagonists & inhibitors; Fibrinogen - metabolism; GPRP Acetate; Healthy Volunteers; Humans; Intestinal Mucosa - blood supply; Intestinal Mucosa - immunology; Intestinal Mucosa - pathology; Male; Mice; Oligopeptides - administration & dosage; Original Research; Proto-Oncogene Proteins c-akt - metabolism; Signal Transduction - drug effects; Signal Transduction - immunology; Vascular Permeability
• ISSN: 2352-345X; 2352-345X
• DOI: 10.1016/j.jcmgh.2020.10.007

Increased vascular permeability (VP) has been indicated to play an important role in the pathogenesis of inflammatory bowel disease (IBD). However, the pathological causes of increased intestinal VP in IBD remain largely unknown. Fibrinogen level was measured in dextran sulphate sodium (DSS)-induced colitis and patients with ulcerative colitis. Gly-Pro-Arg-Pro acetate (GPRP), an Fg inhibitor, was used to detect the effect of Fg inhibition on the pathogenesis of DSS-induced colitis, as indicated by tissue damage, cytokine release and inflammatory cell infiltration. Miles assay was used to detect vascular permeability. Through tandem mass tag–based quantitative proteomics, fibrinogen (Fg) was found to be upregulated in the colon of DSS-treated mice, which was consistent with increased Fg level in colon sample of patients with ulcerative colitis. Gly-Pro-Arg-Pro acetate (GPRP), an Fg inhibitor, significantly alleviated DSS-induced colitis as indicated by improvement of body weight loss and mortality. GPRP decreased colonic inflammation and VP in DSS-treated mice. In vivo, Fg enhanced VP as indicated by Miles assay, which was significantly inhibited by GRPR, AKT (serine/threonine kinase 1) inhibitors and low doses of Jasplakinolide which induced actin polymerization, while was dramatically enhanced by Cytochalasin D (an actin polymerization inhibitor). Moreover, activation of AKT was found in vessels of DSS-treated mice. In vitro, Fg induced activation of AKT and depolymerization of microfilament and promoted cell-to-cell disaggregation. Furthermore, inhibition of AKT decreased Fg-induced microfilament depolymerization. Our findings highlight the importance of Fg in regulating colitis by modulation of VP via activating AKT and subsequent depolymerization of microfilament and suggest Fg as an attractive target for anti-colitis treatment. [Display omitted]