Remodeling of peritoneal-like structures by mesothelial cells: Its role inperitoneal healing

Background Intraabdominal adhesions are a common complication following lap arotomy. Since the exact mechanisms involved in this processes are unknown we have analyzed in vitro the role of mesothelial cells in peritoneal heali ng. Material and methods. Human mesothelial cells from omental tissue were cult ivated for 2 weeks in a three-dimensional culture either on or in a collage n type I matrix. The effects of blood and collagen matrix were analyzed by exposing mesothelial cells to an overlying blood clot, simulating intraperi toneal bleeding, or a second collagen layer. The production of collagen typ es III and IV, fibronectin, and laminin was analyzed with immunohistochemic al methods. Results. Mesothelial cells grown on a collagen matrix formed a monolayer of flat or cobblestone-like cells whereas those cultivated in a collagen matr ix exhibited spindle-like morphology. Mesothelial cells failed to grow into an overlying collagen matrix, but did grow into a blood clot, emphasizing a potential role of blood clots in peritoneal adhesion formation. Independe nt of the culture systems mesothelial cells produced collagen type III, fib ronectin, and laminin but not collagen type IV. Conclusions. Our experiments demonstrate remodeling of peritoneal-like stru ctures by mesothelial cells in a three-dimensional culture reflecting their putative role in the reepithelialization after serosal defects, and also i n the formation of peritoneal adhesions. (C) 1999 Academic Press.