Focal Adhesion Kinase and Colony Stimulating Factors: Intestinal Homeostasis and Innate Immunity Crosstalk.

Thousands struggle with acute and chronic intestinal injury due to various causes. Epithelial intestinal healing is dependent on phenotypic transitions to a mobile phenotype. Focal adhesion kinase (FAK) is a ubiquitous protein that is essential for cell mobility. This phenotype change is mediated by FAK activation and proves to be a promising target for pharmaceutical intervention. While FAK is crucial for intestinal healing, new evidence connects FAK with innate immunity and the importance it plays in macrophage/monocyte chemotaxis, as well as other intracellular signaling cascades. These cascades play a part in macrophage/monocyte polarization, maturation, and inflammation that is associated with intestinal injury. Colony stimulating factors (CSFs) such as macrophage colony stimulating factor (M-CSF/CSF-1) and granulocyte macrophage colony stimulating factor (GM-CSF/CSF-2) play a critical role in maintaining homeostasis within intestinal mucosa by crosstalk capabilities between macrophages and epithelial cells. The communication between these cells is imperative in orchestrating healing upon injury. Diving deeper into these connections may allow us a greater insight into the role that our immune system plays in healing, as well as a better comprehension of inflammatory diseases of the gut.