Role of Klf11 in endometriosis-associated fibrosis.

Endometriotic lesions in Klf11-/- mice were associated with prolific de novo scar tissue formation in contrast to wildtype controls. (A) Adhesions in Klf11-/- animals were thick, opaque, dense and unyielding to mechanical disruption by pressure. The adhesions had a broad base (black arrows) and involved adjacent viscera such as the small and large intestine, stomach and liver, thereby resulting in obliteration of physiological tissue planes. (B) Progressive fibrosis further involved the intestinal mesentery in these animals, resulting in straightening of the bowel with apparent shortening of length (white arrows). (C) In contrast, in wildtype animals, the lesions remained discrete (white arrows and box in C and D) with minimal adhesions (black arrow). Any adhesions that formed were slender, transparent, non-obliterating and very easily disrupted by pressure. (D) Lack of progressive and prolific fibrosis in wildtype animals preserved normal intra-abdominal anatomy with no peritoneal obliteration or mesenteric fibrosis.