ABSTRACT
Intestinal homeostasis is tightly regulated by epithelial cells, leukocytes, and stromal cells, and its dysregulation is associated with inflammatory bowel diseases. Interleukin (IL)-11, a member of the IL-6 family of cytokines, is produced by inflammatory fibroblasts during acute colitis. However, the role of IL-11 in the development of colitis is still unclear. Herein, we showed that IL-11 ameliorated DSS-induced acute colitis in mouse models. We found that deletion of Il11ra1 or Il11 rendered mice highly susceptible to DSS-induced colitis compared to the respective control mice. The number of apoptotic epithelial cells was increased in DSS-treated Il11ra1- or Il11-deficient mice. Moreover, we showed that IL-11 production was regulated by reactive oxygen species (ROS) produced by lysozyme M-positive myeloid cells. These findings indicate that fibroblast-produced IL-11 plays an important role in protecting the mucosal epithelium in acute colitis. Myeloid cell-derived ROS contribute to the attenuation of colitis through the production of IL-11.
ABSTRACT
Interleukin (IL)-11 is a member of the IL-6 family of cytokines and is involved in multiple cellular responses, including tumor development. However, the origin and functions of IL-11-producing (IL-11+) cells are not fully understood. To characterize IL-11+ cells in vivo, we generate Il11 reporter mice. IL-11+ cells appear in the colon in murine tumor and acute colitis models. Il11ra1 or Il11 deletion attenuates the development of colitis-associated colorectal cancer. IL-11+ cells express fibroblast markers and genes associated with cell proliferation and tissue repair. IL-11 induces the activation of colonic fibroblasts and epithelial cells through phosphorylation of STAT3. Human cancer database analysis reveals that the expression of genes enriched in IL-11+ fibroblasts is elevated in human colorectal cancer and correlated with reduced recurrence-free survival. IL-11+ fibroblasts activate both tumor cells and fibroblasts via secretion of IL-11, thereby constituting a feed-forward loop between tumor cells and fibroblasts in the tumor microenvironment.