Characterizing omental adhesions by culturing cells isolated from a novel in vivo adhesion model.

Abstract

Although it has been established that postoperative adhesions in the peritoneal cavity are the consequence of injury to the peritoneum, there is much controversy over the nature of the cells giving rise to this neotissue. Here, we establish a novel adhesiogenic model in the rabbit to analyze the phenotype and proliferation in vitro of cells comprising adhesion tissue seven days postsurgery. Adhesion-free omentum tissue was used as control. Cells derived from adhesions and from the control omentum were subcultured and characterized through immunofluorescence and Western blotting procedures to determine markers of cell differentiation and pluripotential, and viability and proliferation assays. Our findings indicate the existence of a mesenchymal population in the omentum revealed by markers of pluripotent cells with high angiogenic capacity. This population seems to be responsible for the adhesions formed in response to mesothelial damage. Depending on the local environment, mesenchymal cells are capable of in vivo differentiation towards at least two different cell phenotypes rendering two types of adhesions with clearly differentiated characteristics. One type of adhesion shows a highly vascularized adipose morphology containing cells differentiating into a vascular lineage. The other adhesions are fibrous with large amounts of collagen and comprised mainly of myofibroblasts conferring less compliance to this tissue.