Antithrombin Together with NETs Inhibitor Protected Against Postoperative Adhesion Formation in Mice

Abstract

BACKGROUND/AIMS: Postoperative adhesions may induce adverse outcomes in patients. Adhesion formation is initiated by fibrin accumulation at the surgical site which is followed by local neutrophilia and the establishment of neutrophil extracellular traps (NET). Previous reports have suggested that the preventive efficacy of reagents designed to reduce postoperative adhesion is inversely correlated with neutrophilia and NET production. Antithrombin (AT) is a natural inhibitor of thrombin, a key factor in coagulation. Here, we evaluate whether treatment with AT and/or NET inhibitors prevent or reduce postoperative adhesion formation in mice. METHODS: Mice were treated with AT and/or NET inhibitors before and/or after cecum cauterization and their adhesion scores were evaluated on day 7 post-operation. Immunochemistry/ immunofluorescence analyses were also performed and we used GSK484, an inhibitor of peptidyl arginine deiminase 4 (PAD4), as the NET inhibitor. RESULTS: AT or GSK484 partially rescued postoperative adhesion formation in mice. AT prevented thrombin-induced plasminogen activator inhibitor 1 and interleukin-6 expression in mesothelial cells in vitro. However, AT could not prevent neutrophilia or NETs formation around the injured serosa. Finally, we investigated a combination of AT and a PAD4 inhibitor and found that this could inhibit almost all adhesion formation in these animals. Since AT-inactivating proteases are liberated following NET release, they might dampen the biological action of the AT treatment. This suggests that NET inhibitors might allow AT to exert its full action in the surgically injured serosa.

Neutrophil Extracellular Traps: A Crucial Factor in Post-Surgical Abdominal Adhesion Formation

“…In parallel, research on peritoneal fibrosis highlights the role of inflammation and injury from clinical events like surgery in driving fibrosis through complex interactions among myofibroblasts, leukocytes, and other cell types, contributing to the deterioration of the peritoneal membrane [ 20 ]. Lastly, a study on the combined treatment with antithrombin and a PAD4 inhibitor in mice suggests that this approach effectively reduces postoperative adhesion formation by mitigating thrombin and NET-related processes, offering promising insights into managing surgical outcomes [ 19 ]. Collectively, these studies not only underscore the multifaceted role of NETs in peritoneal adhesion formation but also open avenues for targeted interventions that could ameliorate or prevent the adverse effects of surgical interventions.…”

Platelet–Neutrophil Crosstalk in Thrombosis

“…Given the crucial role of NETs in both venous and arterial thrombosis, it is possible that an inhibitor of NET formation or enhancing NET dissolution would be beneficial. As already mentioned, recent studies in animal models propose the use of PAD4 inhibitors or DNases in the treatment of DVT or MI, to help prevent NET release or promote their dissolution, respectively [ 10 , 46 , 61 , 64 , 65 , 107 , 109 , 181 , 182 , 183 ]. Similarly, experimental mouse stroke models suggest that DNase alone or in combination with thrombolytic agents also have promising outcomes for stroke treatment [ 82 , 92 , 93 ].…”