Effects of macrophage-dependent peroxisome proliferator-activated receptor γ signalling on adhesion formation after abdominal surgery in an experimental model

Endogenous macrophage-specific PPAR-γ signalling affected arginase activity and macrophage polarization, and counter-regulated peritoneal adhesion manifestation. Pharmacological PPAR-γ agonism induced a shift towards macrophage M2 polarization and ameliorated adhesion formation in a macrophage-dependent manner. Surgical relevance Postoperative adhesion formation is frequently seen after abdominal surgery and occurs in response to peritoneal trauma. The pathogenesis is still unknown but includes an imbalance in fibrinolysis, collagen production and inflammatory mechanisms. Little is known about the role of macrophages during adhesion formation. In an experimental model, macrophage M2 marker expression was associated with reduced peritoneal adhesion formation and involved PPAR-γ-mediated arginase activity. Macrophage-specific PPAR-γ deficiency resulted in reduced arginase activity and aggravated adhesion formation. Pioglitazone, a PPAR-γ agonist, induced M2 polarization and reduced postoperative adhesion formation without compromising anastomotic healing in mice. Pioglitazone ameliorated postoperative adhesion formation without compromising intestinal wound healing. Therefore, perioperative PPAR-γ agonism might be a promising strategy for prevention of adhesion formation after abdominal surgery.